Abstract In a previous study, we reported the antispasmodic and gastroprotective effects of the Serjania caracasan a (Jacq.) Willd., Sapindaceae, extract. In the present study, we evaluated the LD 50 , hemolytic and antispasmodic activities of its fractions and characterized its major constituents by isolation and GC–MS. The animals showed non-toxic symptoms with oral doses up to 2000 mg/kg, suggesting a safe oral administration. Furthermore, a low hemolytic activity was detected for the saponin fraction. Antispasmodic activity of the fractions was evaluated through carbachol-induced contractions in rat ileum. The hexane fraction was the most potent (IC 50 68.4 ± 5.9 μg/ml) followed by the dichloromethane fraction (IC 50 161.3.4 ± 40.7 μg/ml). Butanol fraction was the less effective (IC 50 219.8 ± 60.3 μg/ml). The phytochemical study of the S. caracasana fractions afforded the isolation of friedelin, β-amyrin, allantoin and quercitrin. This is the first time that the presence of allantoin and quercitrin in the Serjania genus has been reported. Among the isolated compounds and those characterized by GC–MS, β-amyrin and β-sitosterol were present in the most active fractions, hexane and dichloromethane, and they may be related to its antispasmodic activity. In addition, spathulenol was only found in the hexane fraction and its presence might justify the highest antispasmodic activity observed for this fraction.