This study investigates the impact of five determinants of the rewards system on employee motivation in the context of private schools. A sample of 310 respondents is drawn from the private school teachers of Karachi. The rewards system was measured through five independent variables including salary offered, recognition, promotion, working content, and working conditions. By using exploratory factor and regression analyses, the results show that except salary offer, rests of the four variables have been found statistically significant to predict teacher's motivation. However, the recognition of efforts followed by working conditions have revealed the greatest impact on teacher's motivation. Thus, the management of the private schools should not only recognize the efforts of their teaching staff but also concentrate on revising and enriching their working conditions to increase their level of motivation. A major contribution of this paper from the theoretical point-of-view is that it is possible to observe a negative effect of 'salary offer' towards teacher's motivation particularly in the context of a developing country such as Pakistan. Another valuable finding is that 'salary offer', an important antecedent of employees motivation, although not significantly related to teacher's motivation in this study, is a provider of a very strong motivating factor for predicting teacher's motivation at both primary and secondary level of education. Areas for future research are also discussed.