Since sexual relationship itself is an emotional excitement, one must study it in the context of emotions. Therefore, learning about the manner in which the two important psychological variables of alexithymia and emotional schemas relate and influence sexual dysfunction becomes important. The aim of this study was to examine the moderating role of alexithymia on the relationship between emotional schemas and sexual dysfunctional beliefs in women and men with diabetes. Descriptive correlational methodology was used for this study. A total of 152 individuals (78 women, 74 men) diagnosed with diabetes were selected in person and online, through convenient sampling, who completed Leahy emotional schema scale (LESS, 2002), Farsi Toronto alexithymia scale (FTAS-20, 1994), and sexual dysfunction beliefs questionnaire (SDBQ, 2003) during a 3 month period. For data analysis, Pearson correlation and regression adjustment was used.  Results of this research showed a significant positive correlation between emotional schemas and sexual dysfunctional beliefs and alexithymia and sexual dysfunctional beliefs (p=0/01). Regression analysis indicated that alexithymia played a moderating role between emotional schemas and sexual dysfunctional beliefs (p=0/05). From the research findings, it can be concluded that the link between emotional schemas and sexual dysfunctional beliefs is not merely a simple linear relationship, but can be influenced by alexithymia.