The present paper reports the steady state and transient photoconductivity in amorphous Se80Te20 thin films before and after photocrystallization which is induced by shining white light (1000 lux) for about 18 h. The results indicate that the dark conductivity (sigma(d)) and steady state photoconductivity (alpha(ph)) increase by many orders of magnitude on crystallization. The transient behaviour is also affected on photocrystallization.