Fangs of 138 Vipera russellii were examined to determine the changes occurring during fang growth. Fang growth is closely correlated to increases in body and head length. Growth rates and changes in proportions of fangs are rather constant. Changes in such fang proportions as thickness, lengths of the entrance lumen, discharge orifice and points distal to discharge orifice are closely correlated with fang length. Vipera russellii fangs averaged 5.74 mm (1.5-13.0 mm) in length. Mean B/F was 99.92 (78.8-148.0) and mean H/F was 5.15 (3.4-8.9). In mean and maximum length V. russellii compares favorably with most pit vipers (Crotalinae) and ranks intermediate among the true vipers (Viperinae). There is no sexual dimorphism in fang lengths. Fang replacement patterns and rates are discussed.