The Coparenting Relationship Scale (CRS) is a 35-item parent-reported questionnaire designed to assess the quality of the coparental relationship. It was designed in the United States and validated in English. We present in this article a French adaptation of the CRS. A total of 399 participants from the French-speaking part of Switzerland (146 fathers, 253 mothers) completed the questionnaire. Confirmatory factor analysis showed that the theoretically grounded seven-factor structure of the original instrument was valid to explain the structure of the Swiss data. Metric measurement invariance was achieved when comparing mothers and fathers, but only configural invariance was achieved when comparing the original US sample and the Swiss sample. Intercultural differences may possibly explain this result. Convergent validity was tested against parent-reported task sharing and health-related issues in children. Results of multiple hierarchical regression analyses showed theoretically coherent links between the dimensions of the French version and these variables. The French version of the CRS is thus a valid instrument to assess the coparental relationship.