Moonlighting is considered as a dual career or multiple jobs that are carried out by an individual employee. Moonlighting does not only act as the supplement to the main income, but also polish the skills and expand the expertise of public officials. The trend of moonlighting among public officials has become very common. Hence, the concern is how public officials accurately manage their interest instead of giving full commitment to their primary job. This study examines the occurrence of moonlighting factors and job performance among the staff of Public Hospitals in Malaysia and the reasons these issues are debated constantly. The type of investigation of the present study is a causal study considering that this study is conducted for determining the important factors associated with the moonlighting practice among public officials. A set of administrative questionnaires was distributed to the respondents in order to obtain an important view regarding the moonlighting activity. The data collection process was conducted on 104 respondents for quantitative findings, and 5 respondents for the qualitative approach at four public hospitals in Malaysia, namely Hospital Kuala Lumpur, Hospital Ampang, Hospital Tengku Ampuan Rahimah, and Hospital Putrajaya. Additionally, this study also explores three factors of self-efficacy, which were derived from Social Cognitive Theory, namely the environment factors, personal factors, and behaviour factors. This study finds that it is significantly different for at least one of the factors of this study (F=9.034, p< 0.001). The most influential factor reveals that the environment factor is the main factor that influences the primary job performance (p<0.05, ß=0.405). The findings of the process analysis state that only one factor was shown to have moderate relationships between moonlighting factors and primary job performance: personal factor (p<0.05, Int_1.0246 [LLCI=.0250, ULCI=.3568]). This study reveals that moonlighting factors significantly influences the primary job performance of the staffs at Klang Valley Public Hospitals, which is partially supported by the qualitative findings. The result of qualitative findings reveals that moonlighting factors affect primary job performance of the staff at public hospitals. Based on the qualitative findings, tiredness and demotivation are related to job performance issues. This study manages to provide useful information and propose a very effective and good process environment to both public officials and management of the particular organization. The significance of this study refers to the interesting coverage on the theoretical perspective (self-efficacy concept) as well as managerial perspective, which include the government, ministry, staff, academician, and public.
