ABSTRACT. Queiroz G.B., Farache R.A.B., Costa M., Santos M.C.S. & Alencar N.X. [Use of Luxol Fast Blue for differentiation of bilirubin and lipofuscin pigments in liver cytological samples of dogs (Canis familiaris) with hepatic disease.] Uso do Luxol Fast Blue para diferenciação de pigmentos de bilirrubina e lipofuscina em amostras citológicas de fígado de cães (Canis familiaris) com doença hepática. Revista Brasileira de Medicina Veterinária, 38(1):61-64, 2016. Programa de Pós-Graduação em Medicina Veterinária (Clínica e Reprodução Animal), Universidade Federal Fluminense, Rua Vital Brazil Filho, 64, Vital Brazil, Niterói, RJ 24230-340, Brazil. E-mail: email@example.com Several pigments can be viewed on cytological preparation of the liver. Special stains are often necessary to differentiate these pigments, such as the differentiation between bilirubin, pathological pigment indicative of cholestasis, and lipofuscin, a non pathological pigment that is normal in older dogs with the Luxol Fast Blue special stain. The objective of this study was to evaluate the use of Luxol Fast Blue in liver samples obtained from dogs with laboratory and / or ultrasound diagnosis of liver disease with suspected cholestasis, evaluating whether this staining can be used to confirm the diagnosis of cholestasis by cytological examination. 30 dogs underwent ultrasound-guided fine needle aspiration of the liver, followed by serum biochemical test for cholestasis confirmation, of which 11 had suggestion of bilirubin or lipofuscin pigment. The samples were stained with Giemsa and later by Luxol Fast Blue. Although this technique positively stain the lipofuscin pigment, there was no significant difference between samples stained positively and negatively by Luxol Fast Blue in the biochemical evaluation of the animals.