The laboratory is an important service sector for providing scientific data. In a laboratory, the test results accuracy is an important thing, but apart from that in the operational process, the laboratory is also related to environmental aspects. The resources used and the waste produced need good management so that they can minimize the negative impacts on the environment. The focus of this study is a private environmental laboratory in Jakarta which has certified for the environmental management system (EMS) ISO 14001:2015. This study investigates the effect of implementing ISO 14001 on laboratory environmental performance. The method used is a descriptive analysis by evaluating the environmental performance of the laboratory after the application of EMS ISO 14001. The study used secondary data, reference data, and interviews with the key person in the laboratory. Upon the data analysis, the result shows environmental performance indicators that have been achieved base on the organization goals are emission test result that is meet the requirement, and minimize groundwater usage meanwhile the organization still have to improve the wastewater and hazardous waste management.