In vitro organogenesis of 'Carrizo' citrange (Citrus sinensis L. x Poncirus trifoliate Raf.) and 'Cleopatra' mandarin (Citrus reshni Hort. ex. Tan.) was studied considering three explant types: cotyledon, epicotyl and root explants. The explants were cultured in MS (Murashige and Skoog, 1962) medium supplemented with 0.0, 2.5, 5.0 mg L-1 6-benzyl-aminopurine (BAP) with 0.5 mg L-1 naphthalene acetic acid (NAA). Compared with cotyledon and epicotyl explants, a higher percentage responded and a higher number of shoots per explant were obtained with root explants, regardless of the 2.5 mg L-1 BAP and 0.5 mg L-1 NAA concentration (4.9 shoots/explant) in 'Carrizo' citrange. Cotyledon explants for both genotypes were not responsive in all plant growth regulator (PGR) concentrations and combinations studied. Only callus formation was obtained from root explants of 'Cleopatra' mandarin in all different PGR concentrations and combinations. 0.5 mg L-1 NAA without BAP gave the best results for shoot formation of 'Cleopatra' mandarin.