Flexible working methods have become more popular, because they increase employees' quality of life. The number of Turkish firms that support flexible working models and help employees coordinate their work and personal life better are increasing, because employers consider their employees' personal lives as more important. Changes in sectoral scope also played an important role in creating flexible working methods. For instance, the service sector's need to support long-term projects in shipping, banking, telecommunication, press, and oil led to new work processes to focus on customer satisfaction while introducing more flexible working methods. This study presents the effects of flexible working methods on employee performance. It found that flexible working models are very precious for the improvement of and the sustainability of employee performance. According to the results many of flexible methods factors including job's suitability for flexibility, job loyalty and attitude towards flexible working hours directly affect the employee performance.