A series of new 7 beta-[3-(un)substituted-alanyl]-3-vinylcephalosporins and some related compounds, 4a-l is described. They incorporate residues of proteinogenic L-alpha-aminocarboxylic acids, their antimetabolites and enantiomers as well as a dipeptide in the 7 beta-acylamido side chain. The acylation of diphenyl-methyl 7-amino-3-vinyl-3-cephem-4-carboxylate (2: R2 = DPM) with various protected alpha-aminocarboxylic acids 1a-k and the dipeptide 1l is carried out using TBTU as coupling reagent. The compounds, except 4f, are active in vitro against S. aureus and S. lutea, but only 4a, 4k, and 4l inhibit some of the Gram-negative strains.