Background: The causes of work accidents in general are unsafe acts (unsafe behavior) and unsafe conditions (unsafe conditions). The program for implementing the Hazard Observation Card as one of the leading Employee K3 Indicators is a form of focus that is observed on human factors. In several cases of major accidents that have occurred, the root of the problem that caused the accident came from human factors. Objective: This research aims to study the application of the Hazard Observation Card program as an indicator for Employee K3 Assessment at the Inspection Services Company PT. EA Jakarta. Method: This research is a form of observational research using descriptive research analysis that describes, describes and describes the research object. This research was conducted using a cross-sectional approach. Cross-sectional research is research in which all variables are measured and observed at one time (one point in time). The data used in this research comes from observations of the work environment and secondary company data. Results: Based on the data obtained, it is known that unsafe actions and unsafe conditions will still be found in 2023, namely 30% for unsafe actions and 80.95% for unsafe conditions. Unsafe conditions are dominated by employees' lack of neatness while working. The Hazard Observation Card Program is carried out by all workers with two-way communication. The data analyzed is data taken during 2023. And every Hazard Observation Card that is entered into the K3 department will immediately carry out interviews and close the findings. The Hazard Observation Card is used as an indicator of the level of workers' concern for K3, considering the many and complex potential hazards in the office environment of the Inspection Services Company PT. EA Jakarta. Conclusion: Implementation of the implementation of hazard observation cards in the office environment of the Inspection Services Company PT. EA Jakarta is in accordance with Law no. 1 of 1970 Article 9 Paragraph 3 concerning the development of workers to improve occupational safety and health. Hazard Observation Card Program at inspection services company PT. EA Jakarta has been running quite well, with 88.88% of employees participating in observing and filling out hazard observation cards in 2023. Implementation of the Hazard Observation Card is a Leading Indicator in Monitoring and Evaluation of K3 Performance. © 2024, Muhammadiyah Palu University. All rights reserved.