Until recently, hospitals have adapted a series of quality standards to improve the quality of their services. However, these standards do not provide any cost reduction that is worth mentioning within which qualified personnel, material and indirect costs are already very high. To overcome this problem, lean production techniques have been integrated to the healthcare processes in the last few years. This study aimed to reduce costs by both improving and shortening the time of Social Security Instituition (SSI) based invoicing processes of a public hospital in Bursa, Turkey during the period of 2013-2014. To accomplish this goal various lean tools such as value stream mapping, poka-yoke, kaizen and standardization were presented and implemented. For validation purposes, montly SSI cuts, total income and process times before and after the lean transformation were analysed and compared. Furthermore, patient satisfaction surveys were carried out in order to investigate the negative effects of cost oriented lean studies. Results reveal that a clear improvement in total income is achievable, while maintaining the patient satisfaction levels. In this case, an eight percent improvement in SSI cuts resulting in a clear improvement on total income values has been obtained. Findings indicate that implementing lean tools on hospital processes is an effective way to reduce the healthcare costs while maintaining the patient satisfaction levels. The results of this study will stimulate the research in adopting lean techniques not only for patient satisfaction, but also for cost reduction purposes in hospitals.