KVARK D.O.O. is a Serbian company founded in 1992 and based in Kragujevac. It began as a medical-biochemical laboratory and has since developed expertise in radiotherapy, nuclear medicine, and protection from ionizing radiation. With around 30 years of experience, the company supports clients throughout projects by combining specialist services, equipment, and technical assistance.

Its services include radiation monitoring and dosimetric checks, radiation safety design, quality control of devices, medical equipment servicing, commissioning linear accelerators, and the transport of radioactive materials. KVARK also provides medical-biochemical laboratory services.

The company represents and distributes equipment from international manufacturers for medical and industrial applications. Its portfolio covers nuclear medicine, radiotherapy, radiology, laboratory work, radiation detection and monitoring, radioactive waste management, and protective equipment. Products include dosimeters, contamination monitors, imaging and testing systems, shielding, and NDT inspection equipment, as well as industrial technologies such as XRF analyzers, thermal cameras, and neutron generators. KVARK also offers medical software for radiotherapy and treatment planning, along with maintenance and servicing for supplied equipment.