Although research has increasingly recognized that parents benefit from parent empowerment programs, studies on the outcomes of the capacity‐building of practitioners of such programs are generally lacking. Using the results of a non‐randomized controlled trial, this study examined the possible outcomes of a related capacity‐building program. A total of 56 practitioners were recruited from 10 social service agencies in Hong Kong to participate. Most of them were females with more than 10 years of social work experience. Of these, 28 participated in a 15‐session capacity‐building program on parent empowerment (serving as the experimental group), while the others did not participate in the capacity‐building program (serving as the control group). MANCOVAs were performed to identify any differences between the two groups at different time points. The post‐test assessment showed that the level of attitudes around parent empowerment of the experimental group was significantly higher than that of the control group with a large effect size, but no difference was found in their self‐perceived competence. Furthermore, the follow‐up test revealed that the level of self‐perceived competence of the experimental group was significantly higher than that of the control group, with a large effect size. A serial mediation of the levels of favorable attitudes at the post‐test and follow‐up test on the association between the capacity‐building program and self‐perceived competence at the follow‐up test was also found. This study can contribute to the limited body of knowledge on how to equip practitioners with the professional attitudes and skills to implement parent empowerment programs.