Background & Aim: Given the importance of mothers’ health and considering that developmental delay in children affects their mothers’ mental health this study aimed to compare stress and perceived social support in mothers of 6-18 month old children with and without developmental delay.

Methods & Materials: This cross-sectional, analytical study was performed on 610 mothers and their 6-18 month-old infants in health centers affiliated to Shahid Beheshti University of Medical Sciences. The participants were selected through the multi-stage random sampling. To collect data, the following questionnaires were used: obstetric and demographic characteristics, socio-economic status, infants’ characteristics, the Cohen perceived stress scale, perceived social support, and Ages and Stages questionnaire to determine the children’s development status. The data were analyzed by SPSS v.19 software and using descriptive statistics, Pearson correlation, chi-square, independent t-test and Man-Whitney statistical tests.

Results: The mean age of infants were 10.68±4.5 months. Independent t-test revealed a significant difference between mothers’ perceived stress (P=0.004) and social support (P=0.01) in the two groups. In addition, a relationship was observed between the mother’s social support and stress (P<0.04).

Conclusion: The results showed that mothers of children with developmental delays have more stress and lower perceived social support than mothers of normal children. Therefore, it is recommended to perform developmental screening for further examination and the reduction of mothers’ stress, as well as to provide appropriate social support.