A new moss species, Didymodon coquimbensis J. A. Jiménez & M. J. Cano, is described from Coquimbo Region in northern Chile. It is characterized mainly by its spirally twisted leaves when dry, the red to orange color in KOH, leaf apex strongly cucullate, costal guide cells in three layers with 5–9 cells in each layer, and a bulging ventral costal pad of cells. Drawings and SEM photographs of the main characters are given, and possible confusion with other closely related taxa is discussed.