Background: The study is aimed at developing a new measure devised to evaluate gains associated with caregiving for a person with dementia.; Methods: We conducted two studies with Spanish informal caregivers. In Study 1 a total of 152 participants responded to a preliminary set of 62 items referred to gains related with caregiving. After exploring their psychometric properties, we studied its factor structure, concurrent validity, and internal consistency reliability by means of, respectively, an exploratory factor analysis (EFA), its correlation with the similar measures, and Cronbach's alpha coefficients. In Study 2 we undertook a confirmatory factor analysis (CFA) to obtain further evidence regarding the scale dimensionality and we studied its construct validity by calculating its correlations with the Zarit Burden Interview (ZBI), the Geriatric Depression Scale - Short Form (GDS-SF), and the Satisfaction With Life Scale (SWLS).; Results: The final version of the Gains Associated with Caregiving (GAC) scale comprised 22 items, all of which seemed to belong to the same factor according to both the EFA and the CFA. The correlation between the GAC scale and similar measures was statistically significant and strong, and the Cronbach's α coefficient was 0.95. Statistically significant correlations in the expected direction were found between the GAC and the ZBI, the GDS-SF, and the SWLS.; Conclusions: The high internal consistency of the GAC scale, and its adequate concurrent and construct validity suggest that it is a suitable instrument for evaluating gains among Spanish informal dementia caregivers.