Construction industry is high-risk industry with large number of accidents. Nepalese construction industries also suffer from numbers of issues related to safety and health. This study aim to assess the implementation status of safety practices and challenges in proper implementation safety practices in building construction projects of Nepal. For this study, primary data and information were collected from 487 out of 500 respondents of different building projects via checklist and questionnaires. Obtained result were analyzed by MS excel and SPSS. Study revealed overall implementation status of safety practices is moderate level as 70.64 percent responses fall under moderate level of bloom cut off category. Result of RII showed that use of barricades, timely maintenance of plants and equipment, first aid facilities, fire safety, emergency exit and insurance policy are relatively most implemented parameters under study. Design review for safety, safety training and job safety plan relatively less implemented parameters and the provision of safety officer and safety audits were absent in majority of building construction projects. PCA analysis results poor safety culture, Poor safety management, Lack of safety knowledge and resources, Lack of safety infrastructures and communication and problem in governance and implementation are major challenges in implementing safety practices.