Two hundred day old guinea fowl keets were reared in free-range intensive system to determine the effect of production system on growth traits. All birds kept indoor until 7 weeks, and half of them had access to outdoor until 18 weeks of age. All birds were individually weighed with two weeks intervals. Feed consumption was determined and feed conversion ratio was calculated. Production system had a significant effect on live weight until 14 weeks of age (P < 0.05) and intensively reared birds had higher live weights. The difference between the weights of free-range and intensive system was not significant between the ages of 14-18 weeks. Mean body weight of guinea fowls in free-range system was 1196.61 g, whereas 1203.8 g in intensive system. Male guinea fowls had significantly higher weights than females at all ages in both production systems (P < 0.05). Male guinea fowls reached 1241.67 g at 18 weeks and females had a mean body weight of 1158.74 g at the same period. Birds reared in free-range system had significantly higher feed consumption at all ages. Production system had significant effect on feed conversion ratio (FCR), and intensively reared guinea fowls had better FCR. FCR of free-range guinea fowls was found as 6.43 and 5.80 in intensive system.