The purpose of this study is to investigate the effect of internal integration on Lame dairy Plc (Sholla milk) company performance (customer oriented performance, supplier oriented performance and financial performance). The current study is considered as a quantitative study, where stratified sampling was employed to collect data through survey questionnaires. The study surveyed the workers at 10 departments of Lame diary Plc. Practical data were collected and used for analysis from 159 workers out of 181 samples. Structural Equation Modeling was employed to test the relationships between internal integration and company performance. The results of the study indicated a positive significant relationship between internal integration and customer oriented, supplier oriented and financial performance. The results also indicated that customer and supplier oriented performance have significant partial mediating effect on the relation between internal integration and financial performance. Finally, the current study recommend considering customer and supplier integration together because they may strongly interrelated and may affect company performance.