This evaluative study attempts to define the contextual determinants of the degree of implementation in the Integrated Management of Childhood Illnesses strategy in Pernambuco State, Brazil. A total of 33 Family Health Program teams were selected from 10 municipalities. In order to define the degree of implementation, the study used a specific score system and the process indicators provided by the strategy. Municipalities were classified as critical, unsatisfactory, and acceptable. All municipalities except for one presented an acceptable degree of implementation in relation to the structure. In relation to process evaluation, two municipalities received one follow-up visit and their scores were unsatisfactory. Four municipalities received two visits, and one was classified as unsatisfactory on the second follow-up visit, while another presented a critical score on the first follow-up visit. Among four municipalities that received three follow-up visits, one was classified as unsatisfactory in the three evaluations. Four municipalities achieved mean unsatisfactory scores, when considering the mean scores acquired in the three follow-up visits. There was no association between the organizational context and degrees of implementation.