To investigate trend and seasonal pattern of occurrence and mortality of motorcycle accidents in patients referred to hospitals of Isfahan. This cross-sectional study was carried out using traffic accidents data of Isfahan province, extracted from Ministry of Health (MOH) database from 2006 to 2010. During the study period, 83648 people injured due to motorcycle traffic accidents were referred to hospitals, all of them entered in the study. Logistic regression model was used to calculate the hospital mortality odds ratio, and Cochrane-Armitage test was used for assessment of linear trend. During the study period, the hospital admission for motorcycle accident was 83,648 and 89.3% (74743) of them were men. Mean age in accidents time was 26.41±14.3 years. The injuries and death sex ratio were 8.4 and 16.9, respectively. Lowest admission rate was during autumn and highest during summer. The injury mortality odds ratio was 1.01 (CI 95% 0.73-1.39) in the Spring, 1.34 (CI95% 1.01-1.79) in summer and 1.17 (CI95% 0.83-1.63). It was also calculated to be 2.51 (CI95% 1.36-4.64) in age group 40-49, 2.39 (CI95% 1.51-5.68) in 50-59 and 4.79 (CI95% 2.49-9.22) in 60-69 years. The mortality odds ratio was 3.53 (CI95% 2.77-4.5) in rural place, 1.33 (CI95% 1.15-1.54) in men, and 2.44 (CI95% 2.09-2.85) in the road out of town and village. In addition, trend of motorcycle accidents mortality was increasing (p<0.001). Motorcycle accidents injuries are more common in men, summer, young age and rural roads. These high risk groups need more attention, care and higher training.