The Escalas de Avaliação da Interação Mãe-Bebé are a portuguese version of the Interaction Rating Scales proposed by Field (1980); aim to evaluate the mother-infant interaction at infants 3 months old. The translated version was administered to 51 mother-infant dyads at 3, 6, and 12 months postpartum. The Portuguese version showed high levels of internal consistency - Cronbachs Alpha .85 (IRSface-to-face infant), .91 (IRS face-to-face mother), .87 (IRSfeeding infant), .82 (IRSfeeding mother) - concurrent and predictive validity and reliability. The Escalas de Avaliação da Interação Mãe-Bebé are an important instrument on the evaluation of mother-infant interaction and it could be used with different samples and in clinical and research contexts.