Lentil rust, caused by the fungal pathogen Uromyces viciae-fabae is a devastating disease and one of the major biotic constraints that can limit lentil production. Even though the northwest of Algeria is known for lentil production, there is no detailed information regarding the distribution, incidence and severity of lentil rust. The surveys were conducted during the 2018-2020 agricultural campaign in three regions of the Northwestern of Algeria (Mascara, Relizane and Tiaret). A total of 15 fields were surveyed. Rust incidence and severity were recorded from and plant samples were transferred to the laboratory for microscopic observation of the fungus. The result indicated that means rust incidence and severity value greater than 83.7% and 7.6, respectively were recorded in all filed surveyed and in the two agricultural years. Disease severity was classified as very high. Thevariety Syrie 229 was highly susceptible to rust disease. Two spore forms uredospores and teliospores of U. viciae-fabae were observed. Rust disease is mostly managed by chemical fungicides, but an integrated management approach that includes cultural measures, the use of resistant cultivars and biological control is recommended to control this disease.