The manufacturing sector in Malaysia has been recognized as an important sector due to its significant contribution toward the nation's economic growth. This sector is the most significant contributor to total exports of the country and the second largest contributor to the gross domestic product (GDP). However, the total shares of Malaysia's manufacturing exports in the world market declined due to competitive and globalized market condition. Consequently, it is essential to investigate the factors that affect operational excellence to remain competitive and achieving excellence in the business. This study aims to examine the internal and external environmental factors that affect the operational excellence in the Malaysian SMEs manufacturing sector. The literature have demonstrated that an investigation on operational excellence lacks particularly in Malaysian SMEs sector. In addition, the impact of internal and external environmental factors on operational excellence has received little attention in the literature especially in the SMEs sector. Therefore, the conceptual model has been developed based on a comprehensive review of the previous study. This paper presents a conceptual framework that investigates the internal and external environmental factors that affect operational excellence as well as their relationship on operational excellence in the Malaysian SMEs manufacturing sector. The contribution of this paper is to identify the influence of internal and external environmental factors towards the operational excellence. Thus, this study proposed a conceptual framework for SMEs manufacturing sectors in Malaysia.