The first connection between Siena and Grosseto was completed in 1872 by the Società per le Strade Ferrate Romane, first using the Central Tuscan Railway down to Asciano, before using the whole length of the Asciano-Monte Antico railway up to Monte Antico and continuing to Montepescali on the Tirrenica railway, before using this line to run into Grosseto.
In 1906, a proposal was submitted to construct a faster line between Monte Antico and Siena via Buonconvento. The contract to construct this line was awarded in 1910 to the Société Française de Chemins de Fer en Toscane, and the line began construction in 1923. Two years later, the contract was modified and the Società Italiana per Imprese Ferroviarie e Lavori Pubblici (SIF) was awarded the contract to finish the line, which it completed in 1927. The line was inaugurated on 30 May 1927, and served the old Madonnina Rossa station in Siena until the new station was completed in 1935.
The line suffered serious damage during the Second World War and was only reopened in 1951. In 1955, the FS took over operation of the line. On 16 June 1966, floods damaged large sections of the line, and along with the Asciano-Monte Antico railway, the line did not reopen until May 1980, during which period the line was modernised.
In October 2013, a flood washed away the trackbed near Murlo station, which meant the line was closed for a year between Buonconvento and Montepescali.[1][2] The line has also been victim to other floods more recently that have caused the line to be temporarily closed on multiple occasions. Most recently, the line was closed between Buonconvento and Montepescali between 21 December 2022 and 10 December 2023 due to landslides between Buonconvento and Monte Antico. When service was reinstated on 10 December 2023, the service was reduced to only four direct trains between Siena and Grosseto, the remainder terminating at Buonconvento. Also, the station at Murlo no longer has any scheduled trains.
