Six referendums were held in Switzerland during 1938.^[1] The first four were held on 20 February; the first on amending articles 107 and 116 of the constitution to make Romansch an official language, which was approved by over 90% of voters and all cantons.^[1] The second was on a popular initiative "on urgent federal resolutions and the protection of people's rights" and was rejected by 85% of voters.^[1] The third was on a popular initiative on the private arms industry, and was also rejected by a wide margin, whilst the fourth was on a counter-proposal to the arms industry question, and was approved by voters.^[1] The fifth referendum was held on 3 July on the penal code, and was approved.^[1] The sixth and final referendum of the year was held on 27 November on a federal resolution on the transient order of the federal budget, and was approved by 72% of voters.^[1]

The referendums on making Romansch an official language and the federal budget were both "obligatory" referendums,^[1] requiring a double majority; a majority of the popular vote and majority of the cantons.^[2] The decision of each canton was based on the vote in that canton.^[2] Full cantons counted as one vote, whilst half cantons counted as half.^[2] The popular initiatives on federal resolutions and the arms industry also required a double majority, as did the counter proposal to the arms industry question.^[1][2] The referendum on the penal code was an "optional referendum",^[1] which required only a majority of voters in favour.