Quality Assurance program on using ionizing radiation is mandatory in all EU member states but this is still not implemented in most facilities in Croatia mostly because of a lack of medical physicists in diagnostic radiology. Since public health institutions in Croatia do not employ medical physicists in diagnostic radiology, collaboration between these institutions in west region of Croatia with Clinical Hospital Center Rijeka (CHC) was initiated during the year 2015. Physicists from CHC Rijeka performed periodical Quality Control (QC) tests and were included in optimization process. Results of QC tests during the period of 2 years showed a lot of improvements-equipment is maintained more frequently, some old units were replaced with new ones and all institutions acquired QC equipment so radiographers could perform daily and monthly QC tests. All these activities showed that medical physics support in radiology departments is necessary and can improve clinical practice.