Background The present study investigated the factor structure of positive aspects of caregiving (PAC) scale among primary informal caregivers providing care to persons with dementia (PWD) in Singapore. Methods 282 primary informal caregivers of PWD were recruited from the Institute of Mental Health, and Changi General Hospital and administered the 9-item PAC scale. A confirmatory factor analyses (CFA) was conducted to test the model fit of the 9-item PAC proposed by the scale developer and multiple linear regression was used to investigate the significant socio-demographic correlates. Results CFA showed that the 2-factor structure including ‘Self-Affirmation’ and ‘Outlook on Life’ had an acceptable model fit. After controlling for confounding variables, Malay caregivers were associated with higher scores on PAC and ‘Self-Affirmation’ compared to caregivers of other ethnicities. Caregivers with Secondary or below education level had higher PAC and ‘Outlook on Life’ scores. Caregivers who had received formal training scored higher in PAC, ‘Self-Affirmation’ and ‘Outlook on Life’. Discussion The present study confirmed that the 2-factor structure of the 9-item PAC was suitable for informal caregivers of PWD in Singapore. The findings have important implications for locally available interventions to enhance caregiver’s psychological well-being and reduce burden of care.