Soluble sugar accumulation pattern and contents were studied in two Iranian melon cultivars, ‘Suski Sabz’ and ‘Jalali Zard’ (Cucumis melo L. Inodorous). Sucrose, glucose and fructose contents were determined in different mesocarp tissues of developing fruits during days after pollination (DAP). They were characterised by enhanced accumulation of glucose and fructose during early fruit developmental stages with almost no sucrose detectable. A sharp increase in sucrose occurred from DAP 30 and 40 in ‘Jalali Zard’ and ‘Suski Sabz’, respectively. Then, both glucose and fructose showed a steady decrease with fruit maturation. In mature fruits of both cultivars, an obvious gradient of sucrose accumulation was detected, ascending from pedicel to middle and umbilicus part of mesocarp. Also both cultivars could be considered as high sucrose accumulators. The present results might be useful for future studies on improvement of melon fruit quality.