Euterpe oleracea Mart, commonly known as açaí, is found in the Amazon regions, a fruit typically of common habits in the North and Northeast regions of Brazil, in it there are several pharmacological activities present in the shell, pulp and seed. Açaí has polyphenolic components with antioxidant activities, as well as anti-inflammatory and anticancer activities. This book has current research sources and highlights the effects of the acai seed extract on mammary adenocarcinoma cell lines. Our thanks to the Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA), the Universidade Federal do Maranhão (UFMA), the Universidade Estadual de Campinas (UNICAMP) and the Instituto René Rachou (IRR).