Lentil (Lens culinaris Medik.) germplasm with sufficient winter hardiness to survive most winters in cold northern areas is available. However, the use of that germplasm in breeding programs is hampered by variable winter conditions that make field evaluations needed for effective breeding and selection difficult. Our objectives were to gain additional information on the genetics of winter hardiness in lentil by QTL analysis and to identify markers for use in marker-assisted selection. A total of 106 F-6 derived recombinant inbred lines (RILs) from the cross WA8649090/Precoz were evaluated for winter survival in the field at Pullman, WA, USA, Haymana, Turkey, and Sivas, Turkey, in a randomized complete block design with three replications over 3 yr. Winter survival was based on plant stand counts before and after winter. In addition, winter injury was monitored at Pullman during the 1998-1999 winter season. Mean survival of the RILs was 49.7, 5.3, and 89.5% at Haymana in 1997-1998, at Pullman in 1998-1999, and at Haymana in 1999-2000, respectively. For QTL analysis of winter survival, three QTL were detected at Haymana in 1997-1998, one QTL was detected at Pullman in 1998-1999, and three QTL were identified at Haymana in 1999-2000. Only one of the QTL was common to all environments. For winter injury scores at Pullman in 1999, four QTL were identified that influenced winter survival. Overall results indicated that winter hardiness is influenced by several genes and the cumulative effects of winter stress.