Aim of the study was to investigate the efficacy of the nonsteroidal anti-inflammatory drug carprofen for pain management during and after surgical correction of left sided abomasal displacement (LDA) and possible adverse effects on integrity of abomasal mucosa. The blinded study included 24 lactating Holstein cows with LDA corrected by left flank omentopexy. Cows were randomly assigned to one of 2 treatments, carprofen (C; n = 12; 1.4 mg/kg of Rimadyl, Zoetis, IV) or placebo (P; saline; n = 12) one h before and 72 h after surgery. Local paralumbar nerve blocks and infiltration of the incision line (160 mL Procaine 2%) induced anesthesia. Cows were investigated from the day before until 4 d after surgery. Daily feed intake and milk yield were assessed, and behavior monitored by video recordings. Heart and respiratory rate, body temperature, mean arterial blood pressure as well as blood concentrations of glucose, lactate, β-hydroxybutyrate, nonesterified fatty acids and cortisol were determined in regular pre-set intervals. Macroscopic fecal examination, hemoFec testing for occult fecal blood, analysis of pepsinogen in serum and hematological parameters were carried out to determine adverse effects on abomasal mucosa. Results were evaluated in a mixed model with repeated statement (SAS statistical package; fixed effects: group, time, random effect: cow). A significantly decreased mean cortisol response was detected in cows of group C during the entire period from 20 min before the start of the surgical procedure until 10 h after the operation was completed (time × group P < 0.05). According to results of video recordings after surgery in average cows of C spent significantly (P < 0.05) more time ruminating and presented less pain associated behavior (determined by visual analog scale and multiple pain discomfort scale) than cows of P. Based on macroscopic fecal examination, blood count, the hemoFec-Test and serum pepsinogen concentrations, there was no indication for adverse effects on integrity of the abomasal mucosa. The study demonstrated that the use of carprofen in pre-emptive multimodal pain management increased the wellbeing of the patients without evoking adverse effects.