BACKGROUND To study the incidence of and factors influencing "neck shortening" in elderly patients treated for femoral neck fractures using multiple cancellous screws. MATERIAL AND METHODS Of the 197 femoral neck fracture cases treated via closed reduction and cancellous screws fixation from January 2006 to February 2010, 110 were followed up. Patient age, gender, operative time, implantation method, reduction quality, fracture type, bone mineral density, loading time, length of hospital stay, and Harris hip score 12 months after operation were recorded. The patients were divided into two groups (shortening and non-shortening) based on their X-ray performance during follow-up. The healing rates and Harris hip scores of the two groups were compared, and the influencing factors of femoral neck shortening were analyzed. RESULTS Of the 110 cases followed up, 94.5% (104/110) were healed and neck shortening occurred in 41.8% (46/110) within 12.5 months (mean) after treatment. The Harris hip score of the shortening group was lower than that of the non-shortening group (78±17 vs. 86±23, p=0.048). The fracture healing rates of the two groups were not significantly different (p=0.068). The factors influencing neck shortening were significantly correlated with bone mineral density, patient age, gender, and type of fracture. CONCLUSIONS The incidence of neck shortening in elderly patients treated for femoral neck fracture using cancellous screws was high. Bone mineral density, patient age, gender, and type of fracture were the influencing factors of neck shortening.