Valdi Tomasin was born on 16 September 1928 in Ronchi dei Legionari and lived at Via Brigata Modena 13.
He was arrested together with his father Guglielmo Tomasin following a denunciation during the roundup of 24 May 1944 and taken to the Coroneo prison in Trieste. After interrogation, he was put on transport no. 48, which departed on 31 May 1944 and arrived in Dachau on 2 June 1944, where he was registered under number 69721 as a political deportee (red triangle). On 23 July 1944 he was transferred to Markirch (a subcamp of Natzweiler) and registered under number 23743; he later returned to Dachau, where he was killed on 9 May 1945.
Valdi was a partisan of the Garibaldi Natisone Division, Montes Intendance.