The Antillean manatee (Trichechus manatus manatus) can be found along the Brazilian northern and northeastern coasts. Previous studies on the clinical biochemistry of these animals were conducted in North America and the Caribbean, whereas little is known regarding these parameters in South American manatee populations. Accordingly, the objective of the present study was to examine the hematology and clinical biochemistry of T. manatus manatus of different sexes and environments in Northeast Brazil. Whole blood and serum samples were obtained from healthy individuals from different environments. The hemogram analysis was performed and the levels of blood biochemical components were determined using an automatized platform. The only statistically significant difference observed in the hemogram was a higher number of heterophils in manatees screened at the dry season of the year. Clinical biochemistry profiling revealed that free-ranging manatees presented lower levels of creatinine. Albumin was detected in higher concentrations in animals from rehabilitation captivity and amylase presented higher levels in manatees kept in acclimation captivity. Free-ranging manatees showed higher serum aspartate aminotransferase levels when compared to rehabilitation captivity manatees. These results can aid veterinarians and conservation professionals in the development of better captivity management procedures and in the clinical approach of manatees.This article is protected by copyright. All rights reserved.