Abstract: A new series of N-(pyridylacryl) amino acid derivatives have been designed and synthesized as potential radiosensitizers in an effort to increase therapeutic efficacy with less toxicity. Radiosensitization and cytotoxicity of the newly synthesized compounds upon HeLa-S₃ cells were measured. The main effects of the reduction of the shoulder width and Do value of the survival curve by 3-pyridylacrylsarcosine (3A) and 4-pyridylacrylsarcosine (4A) were observed. This work has demonstrated that this series of compounds, especially 3A and 4A, or their structurally related compounds, showed great clinical potential as radiosensitizers if significant radiosensitizing activity in vivo could be achieved.