The effect of chromium (Cr) and ascorbic acid (AA) as a dietary supplementation on productive and reproductive performanceof chickens was studied under winter conditions of Egypt. Total number of 300 (250 hens+50 cocks) Dokki₄ chickens, of 30 weeks old were divided into 5 groups of 5 replicates each (10 hens +1 cock/ replicate). The remaining 25 cocks were divided into 5 groups of 5 cocks each and housed separately for semen evaluation. Birds in the 1^st group (Cont.+) were kept in controlled normal temperature (CNT,25°C) with 64±2% relative humidity (RH) and fed corn-soybean meal basal diet (16.4% crude protein, 2750 kcal ME/kg diet) without any supplementation. Birds in groups from 2 to 5 were exposed to natural low temperature (NLT, 8-18°C) with 65±2%. These groups were fed either basal diet (Cont.-), or the basal diet supplemented either with either 250 ppm AA, 400 ppb Cr or 250 ppm AA plus 400 ppb Cr. Birds in NLT groups decreased (P≤0.05) relative body weight change (BWC, 8.6%), egg number (12.9%), egg mass (13.5%), laying rate (18.5%), hatchability of fertile eggs (4.6%), sperm motility (5.7%) and response to sheep red blood cells (SRBC's) post-injection at 6-days (13.6%) and at 9-days (25.8%), impaired feed conversion (28.9%) and economic efficiency (EE, 48.1%) and increased feed intake (9.3%), plasma contents of cholesterol (21.3%) and glucose (12.2%) contents and malondialdehyde (MDA) concentration in plasma (105.7%) and in semen (54.1%) compared with control group under CNT. Dietary supplementations alleviated (P≤0.05) the adverse effects of the NLT. Birds fed basal diet supplemented with AA+Cr under NLT had significantly (P≤0.05) improved BWC (5.9%), feed conversion (17.1%), egg number (9.5%), egg mass (5.3%), EE (33.6%), plasma cholesterol (10.9%) and glucose (10.2%), semen MDA (25.8%), response to SRBC's post-injection at 6-days (19.8%) and at 9-days (38.3%), sperm motility (6.2%) and hatchability of fertile eggs (5.2%) compared with control under NLT. There was no significant effect on most semen qualities, body temperature, fertility, hatchability (based on total eggs set) and hatched chick weight. It may be concluded that a dietary combination of 250 ppm of AA and 400 ppb of Cr provides positive effect on the productive and reproductive performance and EE of Dokki₄ chickens under NLT.