Tehran University of Medical Sciences Journal of Biostatistics and Epidemiology 2383-4196 7 3 2021 10 23 244 250 Nafiseh Taei Student Research Committee, Shahrekord University of Medical Sciences, Shahrekord, Iran. Hadi Shahraki Department of Epidemiology and Biostatistics, Faculty of Health, Shahrekord University of Medical Sciences, Shahrekord, Iran , Modeling in Health Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran 2021 04 17 2021 06 20 Introduction: Study of cancer incidence trends can provide better insight for decision-making and considering necessary interventions. The current study was focused on investigating the main patterns in the incidence of gynecological cancers among the provinces of Iran during the last decades. Methods: We carried out an applied longitudinal study through the growth mixture model (GMM), with a concentration on the trajectory of incidence rates. Information about the rate of gynecological cancer incidence (per 100,000) in 31 provinces of Iran during the 1990-2016 period was extracted from the Data Visualization System. Taking into account the p-value of the likelihood ratio test (LRT), the number of main patterns was estimated by Mplus 7.4 software. Results: Tehran province with the incidence of 2.00 per 100,000 was in the first rank in 1990, while in 2016 the highest rate was observed in Yazd province with 9.38 cases. Five main patterns were determined based on LRT. Tehran and Yazd provinces showed the sharpest rise, while Khuzestan, Fars, Esfahan, Semnan, East Azerbaijan, Razavi Khorasan, and Mazandaran provinces belonged to the pattern with a moderate-to-highrising trend. 10 provinces including Kerman, Kurdistan, Gilan, Lorestan, Alborz, Hamedan, Kermanshah, Markazi, Ardabil, and West Azerbaijan were on the other hand categorized in the moderate-rising trend. Sistan and Baluchestan and Hormozgan provinces had a slow-rising pattern, and finally, the remaining 10 provinces had the pattern with a slow-to-moderate upward trajectory.  Conclusion: Due to the considerable rising trend in most provinces in Iran, taking urgent and effective preventive actions seems necessary. https://jbe.tums.ac.ir/index.php/jbe/article/view/480