The paper examines the impact of over-education and under-education on earnings in Pakistan over the period of 1998 to 2004 with using a large cross-section data set representative of Pakistani workers. We found that the incidence of over-education in Pakistan is temporary phenomenon and incidence of under-education has increased over time. The results also reveal that there is trade off between education and work experience. The workers with relatively less experience are more likely to be overeducated and workers with relatively more experience are more likely to undereducated. It has also been found that the reward in term of return to over-education has increased for males from 1998 to 2004 with both mean and mode index. While the reward to over-education for female workers have decreased over time. However, the penalty for under-education is volatile between the periods. It has increased for male workers by using the mean index and decreased under the mode index between 1998 and 2004. While for the female workers the penalty to under-education has decreased over time. This paper examines the incidence of over-education and under-education and their effects on earning of workers for a developing country, Pakistan.