Objective: We studied Congenital hypothyroidism detected by newborn screening programs in the north of Iran. Methods: In this study, the records of all confirmed neonates with congenital hypothyroidism from April 2018 to March 2019, whose information is available in the registration system of the provincial health center; were reviewed.In addition, the family health records were reviewed for other required variables. In case of lack of information, the necessary information was collected by calling the child's family. Data were analyzed with SPSS ver 18. Mean and standard deviation was used for quantitative data and chi-square or Fisher test was used for qualitative data. Results: In 2018, 26738children were born in the Guilan province, of which 65 infants were diagnosed with CH. Accordingly, 2.4 per 1000 live births had CH and this situation was 49/22864newborns born in 2019, i.e., 2.1:1000 live births. Preterm history and low birth weight neonates significantly were more prevalent in CH children in comparison to Healthy children (28.9% preterm vs 9.8%; 21.1% LBW vs 6.8%) Conclusion: This study has shown a higher rate of CH in this area. Differences in the prevalence of CH can be due to maternal, neonatal, geographical, and genetic factors that further studies are recommended.