This research verified different methods of pre-conditioning and concentrations of tetrazolium solutions for quality evaluation of Butterfly pea seed. Seeds collected in Seropédica county (RJ) e Fortaleza county (CE) were submitted to the following methods of pre-conditioning: a) scarification with sandpaper and immersion in water at 25oC for 14 hours; and b) immersion in water at 95oC and left in the same water to rest without heating for 24 hours at 25oC. The teguments of the seeds were removed and the seeds were immerged in 0,1; 0,3 e 1% tetrazolium solution during 2 hours and 30 minutes at 25oC. To verify the reliability of the results through the tetrazolium test, germination test, first counting and index of germination velocity were done. Scarification with sadpaper and immersion in water at 25oC for 14 hours were the most efficient in pre-conditioning Butterfly pea seeds and 0,3% tetrazolium solution for 2 hours and 30 minutes at 25oC allow evaluating seeds of this species.