This study was conducted to determine the effect of rearing partially outdoor and indoor conditions on growth rate and carcass yields of Big-6 heavy white Turkeys. Totally 144 white toms were divided into to 3 groups (Pasture-1, Pasture-2 and Control) with 6 replicates, randomly. Pature-1 (P1) and Pasture-2 (P2) had outdoor access from 42 and 49 days old till end of the trail, respectively, while control group was kept indoor. All birds consumed commercial Turkey breeding feed. At the end of trial, no significant differences were observed in terms of body weight but the best one was the control group. The lower feed consume and the best feed to gain was observed in P1 (3.06) and P2 (3.56) then control group (3.73), which was significantly different (p < 0.05). Outdoor access did not have significant effect on carcass weight, breast meat and legs (Thights + drumstick) but it differed the wings (p < 0.05). As a result, it has been said that Big-6 heavy Turkeys have to be fed in. side without outdoor access so far. According to results of present study, one may say that Big-6 white turkey could be grazed with no deleterious effect on growth performance. However, more study is needed to determine age of access to outdoor and growth performance of Big-6 white Turkeys at different grazing fields.