Sexual dysfunction (SD) is a common but often overlooked symptom in multiple sclerosis (MS). The aim of this study was to estimate the frequency, type, and intensity of SD in our patients with MS and to investigate its influence on all the domains of quality of life. The study population comprised a cohort of 109 patients with MS (McDonald's criteria, 2001). SD was quantified by a Szasz sexual functioning scale. Health-related quality of life was measured by a disease-specific instrument MSQoL-54 (Serbian version). The presence of at least one symptom of SD was found in about 84% of the men and in 85% of the women. The main complaints in women were reduced libido, difficulties in achieving orgasm, and decreased vaginal lubrication; in men, the main complaints were reduced libido, incomplete erections, and premature ejaculation. In women, statistically significant negative correlations between the presence and level of SD and quality of life domains were reached for all subscales (P < 0.01), except for the Pain subscale (P = 0.112). In men, negative correlations were also observed for all domains, but they were statistically significant for physical health, physical role limitations, social function, health distress, sexual function, and sexual function satisfaction (P < 0.01). We found that the presence of all the analyzed types of sexual problems statistically significantly lowered scores on the sexual function and the sexual function satisfaction subscales in both men and women (P < 0.01). The most prominent impact on both domains was observed for the total loss of erection in men and for anorgasmia in women. Our results reveal that frequent occurrence of SD in MS patients prominently affects all aspects of their quality of life.