The objective of this study was to assess hypoxia tolerance in Gymnanthes klotzschiana seeds harvested in two areas (Area 1 - subject to flooding; and Area 2 - not subject to flooding) by the imbibition curve, vigor and germination. Seeds of the two areas were submitted to: one (T-1d), three (T-3d), five (T-5d), ten (T-10d) and twenty days under hypoxia (T-20d); in addition to the control (T-0d). All treatments presented three germination stages. The highest germination was achieved in Area 1 T-1d (90%) and the lowest in Area 2 T-20d (31%). The Area 1 seeds required less time and water content to finish their germination, and they presented greater tolerance to hypoxia; a fact proven by the germination and vigor results. G. klotzschiana seeds harvested in an area subject to flooding are more tolerant to hypoxia and are recommended for restoration projects in this type of area.