One of the main directions in winter durum wheat selection is to breed varieties resistant to the widely spread diseases in the Rostov Region. The development of our own initial material, its study in conditions of artificial infection, selection of resistant and tolerant samples for further introduction into the selection process is of great importance for the solution of this problem. The purpose of the research is to study varieties and lines of winter durum wheat on their resistance to leaf diseases under an artificial infection on the specially created infectious plots. The article gives the results of the immunological assessment of 114 varieties and lines of winter durum wheat to pathogens of brown, yellow, stem rust, powdery mildew, septoriosis (infectious field background) and pyrenephorosis (natural background). It was determined that the majority of varieties and breeding lines were resistant or slightly susceptible to the diseases: 74.3% to brown rust, 84.3% to yellow rust and 77.1% to powdery mildew. Winter durum wheat turned to be more susceptible to stem rust, septoriosis and pyrenephorosis. Only 15.8%, 38.7% and 28.1% of the samples were characterized with high resistance and tolerance to septoriosis, stem rust and pyrenephorosis respectively. The varieties and lines ‘Amazonka’, ‘Agat donskoy’, ‘Oniks’, ‘Lazurit’, ‘Teya’, ‘Irena’, ‘Yakhont’, ‘Yubilyarka’, ‘840/11’ and ‘993/12’ have been found tolerant to each pathogen and possess a group resistance to three-four kinds of diseases. Their characteristics on yield and other economically valuable characteristics and properties have been given. All of them are recommended as sources of sustainability for use in breeding programs.