This study was conducted to compare the social adjustment of the mothers with transsexual children with that of mothers with normal kids in order to find out the negative impacts of having a trans child on social adjustment of mothers. This research had a causal-comparative design. The statistical population of the study comprised mothers with trans children referred to Tehran Psychiatric Institute as well as mothers of normal kids studying at Sina Educational Center, Tehran. The study sample included 80 mothers (40 mothers having trans children and 40 mothers having normal kids studying at middle and high schools). In the present study, the Weissman & Paykel Social Adjustment Scale was utilized which probed social adjustment in six role areas comprising daily work, social and leisure activities, relationships with extended family, role as a marital partner, parental role, and role within the family unit, including perceptions about economic functioning. The result showed that there was a significant difference between social adjustment of mothers with trans children and that of mothers with normal kids (P=0.001). Results of one-way ANOVA demonstrated that there was no significant relationship between the demographic variables, i.e., children’s age, mothers’ age, the length of marriage, mothers’ education level, number of children, and birth order, and social adjustment of mothers with trans kids. Based on the research findings, it can be stated that the social adjustment of mothers with trans children is lower than that of mothers with normal kids.