Senna spectabilis DC. is a small tree, 3 to 5 m, found in tropical areas in Africa, Asia, Australia, Latino and South America. It is used in traditional medicine in Cameroon to treat many diseases (constipation, insomnia, epilepsy, anxiety, etc.). Therefore, the aim of this study was to look scientifically for the anticonvulsant and sedative properties of S. spectabilis. In vivo animal models of epilepsy (Maximal Electroshock (MES), N-Methyl-D-Aspartate (NMDA), Pentylenetetrazol (PTZ) and Strychnine (STR) induced convulsions or turning behavior) and insomnia (diazepam-induced sleep) were used. Mice were divided in six groups: one negative control group, one positive control group and four groups treated with the plant extract, (except for diazepam-induced sleep test). Four doses of the ethanolic extract were used: 100, 200, 500 and 1000 mg kg-1. The ethanolic extract of the leaves of Senna spectabilis strongly increased the total sleep time induced by diazepam (p<0.001). It also protected mice against Maximal Electroshock (MES) (p<0.01), pentylenetetrazol (p<0.001), picrotoxin (p<0.01) strychnine (p<0.01) and n-methyl-d-aspartate (p<0.001)-induced seizures and turning behavior and increased the latency to the onset of seizure in Isonicotinic Hydrazide Acid (INH) test (p<0.01). The results lead to the conclusion that the extract of Senna spectabilis possesses anticonvulsant and sedative properties in mice and could explain its used in traditional medicine in Africa, in the treatment of insomnia and epilepsy.