The aim of this research was toevaluate how postharvest exposition to ultraviolet C (UV-C) and fluorescent light affects the developmentof P. carotovorum soft rot as well as the accumulation of -chaconine and -solanine, sprouting, weightloss and soluble solids content in potato seed tubers ‘Agata’ and ‘Monalisa’. Susceptibility of P. carotovo-rum to UV-C light was first in vitro tested.