In order to study the sensitivity of pearl millet to photoperiod, three and four week-old seedlings were exposed to three different photoperiod (8, 12, 16 hours a day) conditions. Plant weight, heading date, seed filling period, grain weight per panicle and grain yield per plant were sensitive to photoperiod. ‘The 16 hour photoperiod increased plant weight, heading date and seed filling period but decreased grain weight per panicle and grain yield per plant. Number of productive panicles, panicle length and panicle weight were relatively insensitive to photoperiod. Seedling age contributed to photoperiod sensitivity for grain weight per panicle. Comparing with 12 hour periods, heading date was 5 days earlier for 8 hour periods and 10 days later for 16 hour periods. Facultative short-day was confirmed for photoperiod response.