Aim The study aimed to investigate the factors that influence parental self-efficacy and to examine the roles of psychological flexibility, mindful awareness, and self-compassion in promoting parental mental health outcomes and self-efficacy in providing care for children with or without congenital hearing loss (HL). Design A descriptive, cross-sectional study. Methods Cross-sectional data from 540 parents of children with (Sample 1; n = 204) or without (Sample 2; n = 336) congenital HL were collected through online questionnaires. The researchers constructed a mediation model and conducted various statistical analyses, including stepwise regressions, t tests, correlations, and mediation analyses. Results The results indicated that for parents of children both with and without congenital HL, parental mental health symptoms (e.g., parental stress, depression, and anxiety) were negatively associated with parental self-efficacy, psychological flexibility, mindful awareness, and self-compassion (r values ranged from 0.68 to 0.27, all p values < 0.01). The results revealed that parental mental health symptoms had direct (beta ranging from -0.29 to -0.18) and indirect effects (beta ranging from -0.85 to -0.33) on parental self-efficacy in both groups. Psychological inflexibility (beta ranging from -0.39 to -0.18), mindful awareness (beta ranging from -0.22 to -0.07), and self-compassion (beta ranging from -0.29 to -0.08) mediated the relationship between mental health symptoms and parental self-efficacy. Among these factors, psychological inflexibility emerged as the strongest mediator and predictor (with the proportion mediated ranging from 32.50% to 38.10%). Patient or Public Contribution The participation of parents in this study provided valuable insights into the factors that influence parental mental health outcomes and self-efficacy in providing care for children with or without congenital HL. Nurses could develop interventions such as workshops, support groups, and individualised care plans that target psychological flexibility, mindful awareness, self-compassion, and mental health support, which have the potential to increase parental well-being and improve confidence in caregiving.