Phenotypic description helps in assessing the physical attributes of species and is also an indicator of the relevance and importance attached to such attributes in their natural environments. This study was conducted to describe patterns and distribution of phenotypic diversity in Nigerian Muscovy ducks. One thousand and twenty (1 020) adult male and female Muscovy ducks reared extensively were randomly drawn from the Rain Forest, Derived Savanna and Guinea Savanna agro-ecological zones/ecotypes and were visually appraised and scored for plumage, skin, shank, feet/web, bill, bean and caruncle colours. Data on qualitative traits were analysed with descriptive statistics (percentages) while fixed effect model was used to investigate relationship between plumage and skin colours and body weight. Results revealed variations in qualitative traits; however, across ecotypes, the predominant plumage, skin, shank, feet, bill, bean and caruncle colours were mottled (45 percent), white (88 percent), yellow (50 percent), yellow (60 percent), black (58 percent), black (69 percent) and red (84 percent), respectively. Besides, significant (P < 0.05) association was observed between plumage and skin colours and body weight. The reported variations in phenotypic traits of Nigerian Muscovy ducks indicate diversity in their genome, absence of selection and the need for their selection and improvement.