Cereus jamacaru DC. has direct use for humans in the treatment of diseases and in diet; it can also be given to animals as forage and used as adornments. Their propagation from seeds is not yet known. The experiment was conducted at the Laboratory of Seed Analysis at the Center for Agrarian Sciences of UFPB, in Areia – Paraiba State, northeastern Brazil, with the objective of verifying the effects of different temperatures and substrates on the germination and vigor of C. jamacaru seeds. The experiment was conducted in an entirely randomized design, in a 3 x 3 factorial scheme: three temperatures (25, 30 and 20-30°C) and 3 substrates (paper roll, between and on-paper), with four repetitions of 25 seeds. The employed tests were: germination, germination speed index (GSI), length and dry mass of seedlings. Germination tests were carried out using transparent plastic boxes (gerbox) in BOD chambers, set in the temperatures of 25, 30 and 20-30°C; the substrates used were paper roll, between and on-paper. Vigor was evaluated through the germination speed index (GSI), length and dry mass of seedlings. The temperature of 25°C is not adequate for germination and vigor tests. The paper roll in constant temperature of 30°C substrate proved more appropriate for conducting germination and vigor tests in seeds of C. jamacaru .