Background and Aims. Functional gastrointestinal disorders (FGDs) are multifactorial disorders of the gut-brain interaction. This study investigated the prevalence of Axis I and spectrum disorders in patients with FGD and established the link between FGDs and psychopathological dimensions.Methods. A total of 135 consecutive patients with FGD were enrolled. The symptoms’ severity was evaluated using questionnaires, while the psychiatric evaluation by clinical interviews established the presence/absence of mental (Diagnostic and Statistical Manual—4th edition, Axis I Diagnosis) or spectrum disorders.Results. Of the 135 patients, 42 (32.3%) had functional dyspepsia, 52 (40.0%) had irritable bowel syndrome, 21 (16.2%) had functional bloating, and 20 (15.4%) had functional constipation. At least one psychiatric disorder was present in 46.9% of the patients, while a suprathreshold panic spectrum was present in 26.2%. Functional constipation was associated with depressive disorders (p<0.05), while functional dyspepsia was related to the current major depressive episode (p<0.05). Obsessive-compulsive spectrum was correlated with the presence of functional constipation and irritable bowel syndrome (p<0.05).Conclusion. The high prevalence of subthreshold psychiatric symptomatology in patients with FGD, which is likely to influence the expression of gastrointestinal symptoms, suggested the usefulness of psychological evaluation in patients with FGDs.