In previous studies have been reported a controversy between the reactivity of mono and polyclonal antibodies in different cells populations of the mouse. In this study we focus on the immunoreactivity of the monoclonal antibody VEGF (C-1) in order to analyze its expression in two cell populations of regenerating mouse liver (hepatocytes and endothelial cells) after partial hepatectomy, and two transplanted hepatocarcinomas (ES2 and SS1K). C3H/S male mice were divided into two groups and kept under standard conditions for circadian periodicity analysis, one group were transplanted with the tumors into the subcutaneous tissue of the animal flank and the other group were subjected to a partial hepatectomy (70 %). The animals were killed by decapitation and exsanguination. Samples of regeneration liver, ES2 and SS1K tumors were processed for histology and immunostained with VEGF (C-1) mouse monoclonal IgG2a antibody. The results showed strongly immunopositivity reaction for VEGF either in hepatocytes or endothelial cells of mouse regenerating liver. We also demonstrated positive immunoreaction in both malignant tumors ES2 and SS1K endothelial and parenchymal cells. We conclude that the use of VEGF (C-1) mouse monoclonal IgG2a antibody can be applied successfully in experimental design leading to study processes involved in mice’s angiogenesisFacultad de Ciencias Médicas