Manufacturing performance measures the extent to which the manufacturing plant has built capabilities like low cost, high quality, delivery, and flexibility. The importance of identifying drivers of these capabilities has been underscored by many scholars although limited evidence exists so far regarding this issue. The available evidence is also primarily based on data obtained from manufacturing firms operating in developed and emerging economies and not from firms in developing economies. This study, therefore, bridges this gap by exploring key internal and external drivers of manufacturing performance taking evidence from the manufacturing sector of a developing economy - Ethiopia. A quant-emphasis mixed method approach was used along with cross-sectional survey design to gather data and answer the research questions in the study. The unit of analysis is the manufacturing plant, and hence primary data was collected using multidimensional questionnaires at plant level from 197 medium and large scale firms from Addis Ababa and its periphery. Secondary data was obtained from census reports, the country’s Growth and Transformation Plan (GTP), and report on the performance of the Ethiopian economy, which were analyzed qualitatively and the implications to manufacturing performance drawn in the study.