The objective of the present work was to classify different rice cultivars for their reaction to the phenol test. The seeds were soaked in distilled water for 24 hours, and then placed in petri dishes on one piece of filter paper moistened with 3ml of 1% phenol solution at 30oC for 24, 48 and 72 hours. The seeds were then examined and grouped according to the colour of the hull. The cultivars Bluebelle, Lebonnet, Bico Torto, Japonês, Farroupilha, Guarani, EEA 404, EEA 405, IAC 25, IAC 164 and EMBR.APA 7, present negative reaction, i.e., did not develop color in the presence of the phenol solution. The cultivars Cica 4, IRGA 408, IRGA 416, BR-IRGA 409, 410, 412, 413, 414, 415, EMBRAPA 6, El Paso 144, ?Colombiano? and Red Rice presents a positive reaction, with variable percentagens of seeds staining of light brown and dark brown. The number of dark brown seeds increase with time of contrast with the solution. The cariopsis (husks removed) did not react to the phenol solution. The phenol test promising as useful supplementary method when testing rice seed samples for varietal purity.