Inappropriate sitting working position among operators in syringe assembly inspection possibly contribute to the issue of several syringes passed the quality inspection and delivered to the clients even they contaminated with over amount of silicon lubricant. This inappropriate sitting posture in the inspection workstation could result the stress, fatigue, musculoskeletal disorder and mental workload issue among operators which influence the operators’ performance. This paper presents an investigation to identify the ergonomics and mental workload issues among the operators in the syringe assembly lines. A series of interview and observations were conducted using ergonomic risk analysis (ERA) checklist to investigate the ergonomics issues. NASA-Task Load Index (TLX) method also had been used as mental workload assessment tool. The results from this study show that there are issues in awkward postures, static and sustained work posture, repetition, lighting and noise. Besides, three out of four operators experience more than 50% score of workload during inspections with the high percentage of five index elements except one operator shows the different result. This study contributes to the study field by verifying the ergonomics and mental workload as significant factor to maintain the product quality and productivity. In future, advanced analysis will be conducted to investigate the identified issues in details and next propose the workstation design improvements.