Safety and health at workplace is an emergent concern in almost all parts of the world including developing countries such as Malaysia. Construction industry is one of the most hazardous industries with regard to work-related injury and fatality rates. Impact on the company would include loss working hours of injured employee, cost of repair and replacement of property and damages as well as increment in insurance premium. The purpose of the study is intended to examine the relationship between factors with safety performance at construction sites. This study investigates whether factors such as working environment, education & training, PPE and weather have any influence on safety performance. The study was conducted among construction workers at Sesco Sub-Station, Balingian, and Sarawak. A set of validated questionnaires were distributed to 100 construction workers. Data were examined based on 95 returned questionnaires (respond rate 95%). Data were analyzed with SPSS version 22 using descriptive and inferential statistics. Pearson's correlation coefficient was used to measure the strength of relationship between independent and dependent variables. It was concluded that the most important factor affecting safety performance of the construction workers at SESCO Sub-Station, Balingian, and Sarawak is PPE.