ABSTRACT Objectives: to analyze predictive factors for the incidence of complications related to peripheral venous catheters in children and adolescents with cancer. Methods: a longitudinal follow-up study, conducted at a pediatric oncology clinic unit of a hospital in Bahia, with 333 peripheral venous catheters inserted in 77 children and 26 adolescents. Data collection took place between April 2015 and December 2016 through direct observation of peripheral intravenous catheter insertion, medical record data collection and daily observation of the puncture site. Results: the incidence of complications was 18.6%. The modeling of the variables confirmed that the risk factors for complications in children/adolescents with cancer were: prolonged peripheral intravenous therapy (p=0.002), history of complications (p=0.000), non-irritating/vesicant medications (p=0.003) and vesicant solutions (p=0.000). Conclusions: the goal has been achieved. Results can contribute to the theoretical, practical and social context.