The aim of this study was to establish the psychometric properties of the new Relationship Satisfaction (RS) scale. Two population based samples were used: The Norwegian Mother and Child Cohort Study (MoBa, N=117,178) and The Quality of Life study (N=347). Convergent and discriminant validity was investigated in relation to the Quality of Marriage Index (QMI), the Satisfaction With Life Scale (SWLS), Relationship Satisfaction of partner, Big Five personality traits (IPIP50) and future relationship dissolution. The full scale with ten items (RS10) and a short version with five items (RS5) showed good psychometric properties. The scale has high internal and test-retest reliability and high structural, convergent, and discriminant validity. Measurement invariance across gender was established. Additionally, predictive validity was evidenced by prediction of future relationship dissolution. We conclude that the RS scale is highly useful as a generic measure of global relationship satisfaction.