OBJECTIVE Every year, several patients are bitten by the common European adder (Vipera berus). The aim of this study is to present a large consecutive case series of patients bitten by V. berus, and to identify signs and symptoms indicative of complicated illness. METHODS This is a retrospective case series from the Hospital of South West Jutland, Denmark. All 219 patients bitten by V. berus (diagnosed by history or clinical findings) from 1994 to 2012 were identified through hospital databases. A severity grading from 1 to 5 was applied, and epidemiology, symptoms and signs, complications, treatment and laboratory data were extracted from the hospital databases. RESULTS The most common complaints on admission were pain, nausea, abdominal pain, diarrhoea and dizziness, with discoloration and oedema being the most common symptoms. Few patients experienced syncope, palpitations or respiratory distress. Fifteen percent of all patients were transferred to the ICU and 2% (all children) were suspected of having compartment syndrome. Leucocytosis, gastrointestinal symptoms and hypotension were risk factors for complicated disease. CONCLUSIONS Most patients only showed symptoms of no or mild envenomation. Fifteen percent were transferred to the ICU and five patients (all children) required fasciotomy because of suspected compartment syndrome. Only 10 patients received antivenom.