OBJECTIVE: To determine of spatial distributions of knife violence in Urmia, Iran, from 20 March 2009 to 21 March 2010. MATERIAL AND METHODS: In this cross-sectional study, we studied the data of 703 new knife-assault victims, who attended to Accident and Emergency departments of three general Hospitals of Urmia, capital of West Azerbaijan province, during a 1-year period. The “Average Nearest Neighbor” method was used to identify the statistically significant geographical clusters. χ test was used for statistical analysis. RESULTS: Countryside areas and shopping centers had significantly the most extensive spatial clusters of knife violence (p<0.001). In summer season, there was different pattern in the clusters of the knife assaults in parks and recreation centers at hours of 19:00 to 3:00, which these data were added to the clusters of the other seasons. Considering space-time and socio-demographic status, teenagers and young single males were commonly as the victims of knife assaults in mentioned areas (p=0.04). CONCLUSION: There is sufficient evidence about existence of knife stabbing violence clusters in Urmia. Understanding that, which areas of city have the high rates of the crime occurrence, provides potentially a unique opportunity for regional planners and policy makers by GIS (Geographic Information System)/GPS (Global Positioning System).