We aimed to evaluate the phytochemical composition of the aqueous extract of leaves of Psychotria carthagenensis, and its possible toxicological effects at 200 µg/Kg on Rattus norvegicus. The aqueous extract was used for preliminary phytochemical analyses using standard procedures. After, male albino Wistar rats (N= 6/group) received by gavage for 15 consecutive days, infusions with fresh (FL) and dry leaf (DL) at 200 µg/kg; controls received filtered water (negative) or clonazepam solution at 0.5 mg/kg (positive). Hematological analyses, determination of serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, uric acid, total plasma protein (TPP), quantification of serum cholinesterase (AChE), and histological analyses of kidneys and liver were carried out. By the phytochemical analysis of the aqueous leaf extract, it was possible to detect the total phenols, flavonoids, tannins and alkaloids, the latter having been recorded for the species for the first time in this study. ALT and AST levels indicated an increase in these plasma enzymes, but histological analysis of kidneys and liver showed only slight changes. Inhibition of AChE levels was related mainly to alkaloids. The infusion showed the pharmacological potential of the plant as an alternative in the treatment of neurodegenerative diseases.