The main purpose of this study, the aim of this course is to evaluate the professional knowledge level of radiotherapy technicians and the effect of working conditions on depression according to sociodemographic characteristics and to investigate whether
there is a relationship between them. The sample of the study consists of radiotherapy technicians who work in hospitals with a bed capacity of 50 and over in İstanbul and nursing program of Health Services Vocational High School Radiotherapy Program. In the study, data was collected in 45 radiotherapy technicians; Beck Depression Scale, World Health Organization Quality of Life Scale Short Form, Minnesota Job Satisfaction Scale and Radiotherapy Technician’s Occupational Knowledge Level and sociodemographic characteristics of radiotherapy technician. The level of professional knowledge of radiotherapy technicians with low depression scores was found to be significantly higher. There was a statistically significant difference between the quality of life quality and physical field scores of the technicians who has administrative duty and their nonadministrative technicians. Data show that the level of depression decreases as professional knowledge in radiotherapy technicians, and there is a difference between future anxiety and quality of life scores. Increasing the level of professional knowledge in healthy institutions, quality and job satisfaction, as well as causing the stress of work is important to eliminate the stress of work.