ABSTRACT Cooperation can be one of the solutions for the competitiveness of small and medium companies, which in general are found in fragmented sectors. Thus, the main goal of this paper is to identify factors that promote or hinder the implementation of cooperation strategies in the knitting cluster of Nova Petropolis (RS). Considering theoretical references on networks and industrial economy, a field research was conducted, interviewing 34 entrepreneurs based on a semi-structured survey. The results indicated a low level of cooperative actions, which are restricted to some production activities and to the promotion of a knitting trade show. One of the greatest difficulties for cooperation is the lack of trust, DESAFIOS A COOPERACAO EM AGLOMERADOS PRODUTIVOS: UM ESTUDO DE CASO NO SEGMENTO DE MALHAS DO SUL DO BRASIL COOPERATION CHALLENGES IN PRODUCTION CLUSTERS: A STUDY CASE ON THE KNITTING SECTOR IN SOUTH BRAZIL LEONARDO NEUMANN lneumann@sinos.net ASTOR HEXSEL ahexsel@unisinos.br ALSONES BALESTRIN