With the properties of interference avoidance and the robustness against multipath channels, Orthogonal Frequency Division Multiple Access (OFDMA) has been considered a promising solution to the interference control problem in femtocells. As a multi-carrier transmission technique, OFDMA, however, is highly vulnerable to the Carrier Frequency Offset (CFO). This chapter discusses the challenges of multiple frequency offsets compensation in OFDMA femtocells. A number of multiple frequency offsets compensation algorithms are reviewed and their complexities are discussed in detail. A new approach that exploits the redundancy offered by cyclic prefix is then introduced to enhance the compensation performance. Finally, numerical results are presented to illustrate the performance of different compensation algorithms.