•Three factors were found: self-oriented, child-centered and family-related reasons.•Being female and younger were positively related to willingness and intention.•Greater child-centered reasons were positively related to willingness and intention.•Parental experience, lower education and more income were related to intention. Research into the reasons that could lead community samples to become foster families is sparse, as most studies focus on the reasons identified by licensed or prospective foster families. The present study aims: (1) to assess the validity and reliability of the Reasons for Fostering Inventory adapted for a community sample (Portuguese version); and (2) to test the role of family factors and the different reasons for fostering as potential predictors of willingness and behavioral intention to foster. The reliability and validity of the inventory were assessed using a convenience sample of Portuguese adults (n = 441), 84 % female, aged 26–74. A three-factorial structure (self-oriented reasons, child-centered reasons, and family-related reasons) composed of 22 items was identified. The factorial structure was tested with a holdout randomization method for cross-validation. All factors were reliable, with internal consistency levels ranging from 0.85 and 0.88. Being female, younger, and scoring lower on family-related reasons and greater on child-centered reasons showed positive associations with both willingness and intention to foster. Lower scores on self-oriented reasons were associated with higher willingness to foster; while having parental experience, lower education, and greater income were associated with a higher intention to foster. This study contributes with additional psychometric evidence for this scale for use with community samples. It also provides new insight into how individual resources may be linked with willingness and intention to foster in a community sample.