The study examined the mediating role of knowledge management in the relationship between strategic orientation and firm performance in southwest Nigeria using a data set of 300 customers and 57 managers of the telecommunication firms which include the customer care staff members. The collected data was analysed using mediation analysis. The results indicate that strategic orientation is positively related to performance by 0.37, while knowledge management is directly related to performance by 0.16. On a direct basis, the result shows that strategic orientation has larger effect on performance than the direct effect of knowledge management on performance. The results showed further that the introduction of knowledge management as a mediating variable improves the relationship between strategic orientation and performance by 0.04. The results lead to the conclusion that knowledge management is nearly indispensable in the role of strategic orientation as a necessary factor in the performance drive of firms.