Objectives:: Fibromyalgia syndrome (FMS) is characterized by persistent widespread pain which greatly impacts the quality of life (QOL). Pain not only limits patients’ daily activities but also restricts their social activities further leading to depression, anxiety, and stress. The present cross-sectional study elucidated the association of sleep quality and mood with increasing symptom severity of fibromyalgia and its impact on the QOL of fibromyalgia patients. Materials and Methods:: Hundred adult fibromyalgia patients diagnosed by the American College of Rheumatology 2010 criteria were evaluated for: sleep – using the Pittsburgh sleep quality index, QOL by SF-36, pain-visual analog scales (VASs) and global pain scale (GPS), mood-depression, anxiety, stress scale-21, somatic symptoms, anxiety and depression – by patients health questionnaire somatic, anxiety, and depressive symptom scales (PHQ-SADS), and FMS severity was evaluated using fibromyalgia impact questionnaire (FIQR). Results:: The mean pain score was 6.80 ± 1.58 on VAS and 54.10 ± 14.33 on GPS. FIQR score was 50.62 ± 13.68, mean sleep quality was poor (9.30 ± 3.88), and depression, anxiety, and stress scores were increased (10.04 ± 4.59, 8.33 ± 4.48, and 10.75 ± 4.66). An increasing trend of depression, anxiety, stress, and somatoform symptoms was observed with an increase in the severity of FMS when patients were compared according to FMS severity scores. Sleep also deteriorated with increasing severity of FMS from 5.66 ± 1.92 in mild FMS to 12.0 ± 3.41 in highly severe FMS patients. The QOL too deteriorated in all the domains with increasing severity. Conclusion:: With the increasing severity of fibromyalgia, not only does the pain increase but mood and sleep quality also deteriorate, which further impacts the QOL of FMS patients. Thus, comorbid mood derangements must also be screened and addressed for maximum benefit of the patients.