Purpose There is no consensus about the correct definition of uncomplicated diverticulitis (UD) in clinical practice. We evaluated therefore whether clinical picture of UD differs from complicated diverticulitis (CD). Fifty consecutive eligible patients (21 males, 29 females, mean age 63.6 years, range 47–75 years) were studied. Symptoms, the inflammatory indices, and Computerized Tomography (CT) scan of the abdomen were assessed at the time of admission. Results Thirty-nine patients classified were affected by UD and 11 patients by CD. CD patients showed more severe clinical picture than UD and required urgent Hospital admission. Conversely, most of the patients affected by UD were treated as outpatients. CD patients showed higher symptom scores than UD patients, except the parameter “diarrhea”. All CD patients showed increases in all inflammatory indices. Conversely, all UD patients showed increased ESR, CRP and fibrinogen, but WBC and α1-acid glycoprotein were increased in only a few cases. CT scan in CD patients always showed signs of severe colonic and pericolonic inflammation. Conversely, UD patients often showed moderate localized signs of inflammation without complication. Conclusions Clinical, laboratory, and radiological findings may easily differentiate uncomplicated from complicated diverticulitis of the colon. This integrated approach may be helpful in clinical settings.