1970s

In 1970, Herrera-Vaillant was recruited by General William Henry Draper, Jr. to serve as Western Hemisphere Resource Development Director at the International Planned Parenthood Federation to promote fundraising on behalf of birth control throughout Latin America.^[3]

After a brief period based in Brazil, Herrera-Vaillant settled in Caracas as a founder and director of Fundación Paternidad Responsible (1971), promoting planned parenthood in Venezuela.^[4]

In 1974 Herrera-Vaillant served as commissioner for Caracas Governor Diego Arria and later as secretary general in Venezuela's newly created Ministry for Information and Tourism (1976–1978).^[5] As such, he served as chairman of the OAS Tourism Commission, of the Caribbean Tourism Association, and the Caribbean Hotel Association; and member of the executive committee of the UN World Tourism Organization, based in Madrid (1977–1978).^[3]

Herrera-Vaillant took part in Venezuela's 1978 presidential campaign ( ) as secretary general of CAUSA COMÚN which was founded by Presidential candidate Diego Arria. After Copei's Luis Herrera Campins was successful, Herrera-Vaillant returned to his consultancy, working with the Latin American Economic System (SELA), the Caracas Chamber of Commerce and as a campaign consultant with Gerald Rafshoon Associates, as a political image and campaign consultant for candidates Luis Bedoya Reyes in Peru; and Napoleón Duarte in El Salvador.

1980s

In 1982 Herrera-Vaillant joined Grupo Cisneros working directly with Gustavo Cisneros as the group's director for institutional affairs for eight years.^[3] During this period he was a four term president of the Cosmetics, Toiletries and Fragrances Industrial Association (CAVEINCA), served as treasurer and Secretary of the board of directors of CONINDUSTRIA, Venezuela's Council of Industries; and as president of the Legislative Affairs, Integration (Andean Pact) and International Affairs Committees of FEDECÁMARAS, the Federation of Chambers of Commerce and Industry, the country's main business organization.^[6] As such, he was private sector chief negotiator in drafting the Consumer Protection, Foreign Investment and Labor laws of the time.

Between 1983 and 1986, Mr. Herrera-Vaillant also served internationally as Hemispheric Secretary General of the Inter-American Trade and Production Council (CICYP), which was the principal group representing private enterprises in the Americas and Spain.^[6]

1990s

In June 1990, Herrera-Vaillant became chief executive officer of the Venezuelan American Chamber of Commerce and Industry (VENAMCHAM), a position he held until April 2006.^[7] During this period the chamber grew into one of the largest overseas American chambers and the most influential business organization in Venezuela.^[8] Corporate membership grew from around 842 to 1200, participating executives rose from 2660 to close to 9000, and staff increased from 17 to 106. Service committees increased from 16 to 38, plus six regional operations were created in Maracaibo, Barquisimeto, Valencia, Puerto La Cruz, Maturín, and Porlamar and Herrera took control of Business Venezuela as editor-in-chief and re-designed it as a monthly magazine, making it profitable and second in circulation for all economic magazines in Venezuela. Herrera also created an "ALIANZA SOCIAL" to identify private sector contributions to social problems, promote corporate responsibility, and foster synergy and strategic alliances to accomplish socially valuable goals. He also created one of Venezuela's first private arbitration centers: The Business Center for Conciliation and Arbitration (CEDCA).^[9]

Herrera-Vaillant led Venamcham's to establish a U.S.-Venezuela Bilateral Investment Protection Treaty (BIT) and helped obtain the passage of a Treaty to Avoid Double Taxation between both nations (1999), as well as the solution of numerous bilateral trade and investment issues, including formation of a Bilateral Trade and Investment Council.^[10]

2000s

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Herrera-Vaillant was active internationally in the Association of American Chambers of Commerce in Latin America (AACCLA), where served as member of the board of director and chairman of the nominating committee, and of the management committee which oversees the functioning of American chambers throughout the Americas. During this time he actively participated in lobbying on behalf of NAFTA, CAFTA and the Chile and Colombia Free Trade Agreements, and was an active speaker on Venezuelan and Latin American issues.^[11]

In 2000, as the Chamber celebrated its 50th anniversary and Herrera-Vaillant served as editor of a 500-page history of bilateral relations in Spanish: "Venezuela y Estados Unidos a través de 2 siglos".^[12]

Upon retiring from VENAMCHAM he founded the Inter American Corporate Advisory Network (I-CAN) to assist corporate regional operations through high-level consulting services in public affairs, business facilitation and opportunity development. I-CAN VENEZUELA became affiliated with the OGILVY Group of Companies; and I-CAN COLOMBIA has been a strategic ally of ARAÚJO IBARRA ASOCIADOS, Colombia's leading consulting firm on international trade.

At the same time, Herrera-Vaillant was appointed Senior International Advisor at TORRES PLAZ & ARAUJO ABOGADOS, one of Venezuela's premier law firms; and was named International Consultant at Venezuela's GLOBOVISION TV Network.

He also served for two years (2007–2009) as Regional representative for ENTERPRISE FLORIDA in Northern South America, with offices he established in Bogotá, Colombia.

In 2009 became International Partner for Venezuela, Colombia, Central America and the Caribbean at UPITE CONSULTING SERVICES S.L. (Underperformance Improving Technologies Enterprise), a Spanish consulting firm that provides revenue enhancement services to banks and other financial institutions.