Objectives A systematic review was conducted to (1) investigate couple functioning after a pediatric cancer diagnosis and (2) examine theoretical and methodological tendencies and issues in this literature. Methods Searches of Web of Science, PubMed, Cochrane, PsycINFO, and Embase resulted in inclusion of 32 qualitative, quantitative, or mixed‐method papers. Findings of these papers were extracted for summary. Results Most couples adapt well to the crisis of a pediatric cancer diagnosis in domains such as emotional closeness, support, marital satisfaction, and general marital adjustment. However, most experience difficulties in the domain of sexual intimacy, and reports on conflict are mixed across qualitative and quantitative studies. Conclusions This review illustrates the need for future research with a greater focus on the impact of a pediatric cancer diagnosis on the couple's functioning, conducted with the use of appropriate theoretical frameworks and based on both partners' reports. Improvements in research are needed to best inform couple‐based interventions.