Parenting self-efficacy is one of the important determinants that assists smooth transition to parenthood and has an impact on the parent–child relationship. The aim of the study was to test the psychometric properties of the Parenting Efficacy Scale (PES) among multi-ethnic parents in Singapore. A descriptive correlational repeated research design was adopted to test the performance measurement among 250 fathers and mothers (125 each). To examine the test–retest reliability of the PES, 211 participants (106 fathers and 105 mothers) were retested 4 weeks after the first test. Demographics such as age, ethnicity, monthly income, gender, and education were used to test the construct validity of the PES. A confirmatory factor analysis confirmed the single factor structure for the PES, fitting both parents. The scale demonstrated good internal consistency and test–retest reliability with Cronbach’s α coefficients of 0.91 and 0.75, respectively and intraclass correlation coefficients of 0.70 and 0.71 for fathers and mothers, respectively. The PES showed good content validity with a scale content validity index of 0.85. Parenting self-efficacy was predicted by age, ethnicity, and monthly household income. The PES is a psychometrically acceptable instrument for measuring parenting self-efficacy among multi-ethnic parents in Singapore. Hence, it can be used routinely to assess parental self-efficacy during the postnatal period.