Objectives: Only a minority of patients referred to specialists with sinonasal symptoms have clear evidence of chronic rhinosinusitis (CRS). This study aims to estimate the prevalence of and associations between (i) general illness factors (fatigue, autonomic dysfunction) and (ii) psychological factors (anxiety, depression, somatisation, personality traits) in patients presenting with sinonasal symptoms. Design: The following validated questionnaires were administered to patients: the Sino-Nasal Outcome Test-22 (SNOT-22) identifying symptom burden, Composite Autonomic Symptom Score-31 (COMPASS-31) measuring autonomic function, Chalder Fatigue Questionnaire, Patient Health Questionnaire-15 (PHQ-15) addressing somatisation symptoms, Hospital Anxiety and Depression Scale (HADS), and the International Personality Item Pool-50 (IPIP-50). Comparisons were made with normative and general population data, and relationships were analysed using nonparametric correlation. Setting: Secondary care ENT outpatients. Participants: Adults referred with chronic sinonasal symptoms. Main outcome measures: SNOT-22, COMPASS-31, Chalder, PHQ-15, HADS, and IPIP-50 questionnaire scores. Results: Sixty-one patients were included. There was a high prevalence of all general and psychological factors assessed compared with controls. Total SNOT-22 scores showed significant correlation with Chalder fatigue scores, total autonomic dysfunction score, anxiety, depression, somatisation tendencies and the emotionally unstable personality trait. Emotional instability and psychological dysfunction correlated significantly with sleep and psychological subscales of SNOT-22 but not the rhinological or ear/facial subscales. Conclusion: Patients with sinonasal symptoms demonstrate high prevalence and complex associations of general illness factors, psychological distress and certain personality traits. The SNOT-22 is a valuable tool, but its utility is limited by correlations with these confounding factors (eg psychological factors) that may exaggerate the total score. The use of the SNOT-22 component subscales is likely to provide more clinically meaningful and discriminant information.