Although some cold tolerant lentils have been recognized for fall planting in the highlands of Northeastern Iran, it is requires more information about the growth and development of these accessions. This study was carried out to evaluate the phenology and morphology of cold hardy lentils in fall planting. Nineteen lentil genotypes were sown during 2007-2008 growing season at the Research Farm of College of Agriculture, Ferdowsi University of Mashhad in completely randomized design with three replications. Days from planting to emergence, vegetative and reproductive duration, growth stage and growth type before severe cold, height of plant at harvest time and number and length of branches per plant were determined. There were significant differences (p≤0.05) among genotypes for these characteristics. MLC25 and MLC20 with 7 and 10 days had the lowest emergence duration. MLC185 with 8 leaves had the most growth rate before cold. Growth type in 5, 8 and 6 genotypes was erect, semi-spread and spread, respectively. MLC29, MLC20 with 159 days and local landrace with 157 days had the most vegetative duration. MLC29 with 43cm was the tallest genotype. The most number of branches were observed in local landrace and MLC20 with 20 and 18 branches, respectively. MLC20 with 340 cm and local landrace with 324 cm had the longest branches. Positive and significantly correlation were observed between vegetative and reproductive growth durations with plant height (r=0.61^** and r= 0.57^**) number of branches per plant (r=0.77^** and r=0.57^**) and length of the branches per plant (r=0.73^** and r=0.49^**), respectively. Also correlation between vegetative growth and reproductive growth was positive and significant (r=0.71^**).