Small and medium-sized enterprises (SMEs) are drivers of Thailand's economy and represent the largest number of all firms in Thailand. SMEs in Thailand always face safety and environmental issues, while worldwide safety and environmental management systems are difficult to implement within limited resources. This research aimed to develop a conceptual framework for an alternative integrated occupational health, safety, and environmental management system (OHS&EMS) that fits the characteristics of small and medium-sized steel manufacturer. This research is qualitative, and a literature review on the safety and environmental management system literature and interviews with experts as well as focus group discussions were conducted. The results were analyzed using content analysis. It was determined that the Plan-Do-Check-Act (PDCA) is the cycle that must be maintained for an alternative integrated management system with key requirements, including organization and stakeholder assessment, hazard identification and risk assessment, environmental aspects, action plans for risk and impact mitigation, internal audit, and corrective action and management review. For the success of alternative management system implementation, communication processes that will convince SMEs to accept and realize the benefits of an integrated OHS&EMS must be carried out prior to its implementation. Less documentation must be considered in order to avoid the difficulty of management system implementation. Furthermore, it is suggested that SMEs need support from external parties in terms of finances and consultation, as well as surveillance audits in order to ensure the continual improvement of their safety and environmental performance. The Thai government should improve the legal framework, provide financial support and training to promote OHS&EMS to Thai enterprises.