The healthcare system is one of the branches of economy particularly sensitive to high quality. Therefore, healthcare facilities must prioritize the process of increasing quality. Improvement and evaluation of the quality is not simple, since the quality consists of both correct implementation of medical services in the light of current knowledge and accepted standards and values which are important for the patient. Forms of improving quality can also take various shapes. One of the external forms of assessment is accreditation of hospitals. Its main objective is a voluntary assessment on the basis of beforehand determined and public standards. It allows to collect data relating to specific areas and the scope of activities of the hospital and also allows to draw conclusions from accreditation process which in turn can lead to improved quality of services and patients safety. This article is devoted to problems of improving the quality of medical services and patient safety in the context of accreditation of hospitals in Poland.