The association between phenotypical and reproductive traits has been the focus of considerable research in decapod crustaceans, particularly with the goal of facilitating the management and sustainable use of natural stocks of commercial interest. The goal of the present study is to evaluate the existence of a relationship between ovarian maturation and the coloration of the ovary and carapace of Ucides cordatus using histological methods and macroscopic observation. Monthly samples of adult females were obtained between October 2002 and March 2005 in mangroves of the Baía de Antonina, Southern Brazil (25 o25'S; 48 o42'W). A total of 367 specimens were collected throughout the study. Each specimen was classified subjectively into five ovarian colorations (whitish, yellow, orange, brown, and purple) and five carapace colorations (yellow, blue, dark gray, brown, and purple). Although substantial differences in ovarian development were found among females with different carapace and ovarian colorations, the variability within each class precluded their use as reliable indicators of ovarian development.