Abstract This study investigated the biometry, pre-germination treatments and substrates for the germination of diaspores of Balfourodendron riedelianum. The diaspores were characterized during germination according to their length, width, thickness, thousand kernel weight (TKW) and water content. Dormancy overcoming was tested by diaspore scarifying with sandpaper, sulfuric acid immersion, water and water at 100 °C; together with the control (untreated), they were associated to different substrates (including paper (EP), sand (EA) and vermiculite (EV). Germination tests were conducted in a germination chamber at 25 °C. The physiological quality of seeds was performed through the first count, germination and germination speed index (GSI). Biometric data were analyzed in frequency classes and the pre-germination treatment by analysis of variance. Diaspores are on average 18.59 mm long; 9.03 mm wide and 9.38 mm thick. The treatment of immersion in cold water for 48 hours and the substrate vermiculite (EV) were effective to overcome dormancy and recommended for germination tests.