The objective of this work, was to study the maturation process of Dalbergia nigra seeds, and determine the best harvest period in the region of Viçosa, Minas Gerais, Brazil. Fruits of D. nigra were harvested in intervals of fifteen days from June to September 1994 in the four trees located in the Federal University of Viçosa. Green and dry matter weight, moisture content, seed dimensions (length, width and thickness) and percentage of germination of seed were evaluated. The analysis of data obtained led to the following conclusions: the physiological maturity of seeds was obtained at 335 days after anthesis; the harvest of the seed should be done between 335 to 350 days after anthesis, from September 15 to September 30; the parameters which best characterized the physiological maturity and the time for harvesting were moisture content and dry matter weight.