The gills contain essential cells for respiration and osmoregulation, whereas the hepatopancreas is the site of digestion, absorption, and nutrients storage. The aim of this work was to separate and characterize gill and hepatopancreatic cells of the mangrove crab, Ucides cordatus. For gills, the methodology consisted of an enzymatic cellular dissociation using Trypsin at 0.5%, observation of cellular viability with Tripan Blue, and separation of cells using discontinuous sucrose gradient at concentrations of 10%, 20%, 30%, and 40%. The hepatopancreatic cells were dissociated by magnetic stirring, with posterior separation by sucrose gradient at the same concentrations above. For gills, a high cellular viability was observed (92.5±2.1%), with hemocyte cells in 10% sucrose layer (57.99 ± 0.17%, *P < 0.05), principal cells in the 20% sucrose layer (57.33 ± 0.18, *P < 0.05), and thick cells and pillar cells in the 30% and 40% sucrose layers, respectively (39.54 ± 0.05%, *P < 0.05; and 41.81 ± 0.04%, *P < 0.05). The hepatopancreatic cells also showed good viability (79.22 ± 0.02%), with the observation of embryonic (E) cells in the 10% sucrose layer (67.87 ± 0.06%, **P < 0.001), resorptive (R) and fibrillar (F) cells in the 20% and 30% sucrose layers (44.71 ± 0.06%, **P < 0.001, and 43.25 ± 0.01%, *P < 0.05; respectively), and blister (B) cells in the 40% sucrose layer (63.09 ± 0.03%, **P < 0.001). The results are a starting point for in vitro studies of heavy metal transport in isolated cells of the mangrove crab U. cordatus, subjected to contamination by metals in the mangrove habitat where they are found.