The species Costus spicatus Swartz, known popularly as “cana-do-brejo,” is widely used in folk medicine in treatment of various health problems, such as pain and inflammation. The present study aimed to identify the main chemical classes present in the crude methanol extract and in the hexane, chloroform, ethyl acetate and n-butanol phases from leaves of C. spicatus, as well as to assess the antinociceptive profile of the organic phases in two tests of nociception: acetic acid-induced writhing and formalin-induced nociception in mice. Phytochemical screening revealed the presence of tannins, flavonoids, steroids and triterpenoids in the crude methanol extract and in all organic phases, and the absence of alkaloids only in the n-butanol phase. The tests were negative for saponins and quinones. In the pharmacological evaluation, at the doses of 50, 100 and 200 mg/kg (by oral route), all organic phases showed antinociceptive activity in the acetic acid-induced writhing test (p < 0.001). In the formalin test, during the first phase, only treatment with the chloroform fraction demonstrated the antinociceptive response (p < 0.05). In the second phase, the hexane, chloroform and ethyl acetate fractions showed an antinociceptive activity (p < 0.05). Furthermore, the organic phases did not impair motor coordination of the animals. Therefore, the results showed antinociceptive activity in all organic phases, except in the n-butanol phase, indicating that these effects were probably due to the presence of secondary metabolites.