This experiment was conducted to investigate the effect of coat characteristics on physiological traits and heat tolerance of dwarf sheep in southern Nigeria. A total number of twenty West African dwarf male sheep with an average weight of 9.00 ± 0.52 kg and aged 10 months old were used for the experiment. The dwarf sheep were assigned to four treatment groups in a completely randomized design with five sheep per treatment group. The compared treatment groups were TA (black coat colour sheep with low coat depth and short hair length), TB (black coat colour sheep with high coat depth and long hair length), TC (light brown coat colour sheep with low coat depth and short hair length) and TD (light brown coat colour sheep with high coat depth and long hair length). The results obtained in the study showed that midday was significantly (P 0.05) affected by morning, midday and evening. Rectal temperature (40.09℃), respiratory rate (21.01 breaths/min), pulse rate (87.49 beats/min), heat tolerance coefficient (97.10%), haemoglobin (9.04 g/l), blood cell (10.84 × 106/μl), white blood cell (12.06 × 106/μl) and glucose (50.10 mg/dl) were significantly (P 0.05) did not occur in total protein, albumin and globulin among treatment groups. It is concluded that coat characteristics have significant effects on physiological indices and heat tolerance in Nigeria.