In a clinical setting, we tested the hypothesis of whether hypercapnia developed during carbon dioxide pneumoperitoneum is associated with changes in blood electrolytes. This prospective study involved ten female cats that underwent elective laparoscopic ovariectomy. Venous blood samples for assessment of electrolytes were collected in the following sequence: T1- before anaesthesia induction, T2 - 10 minutes after anaesthesia induction, T3 - 30 minutes of pneumoperitoneum and T4 - at the end of pneumoperitoneum. Statistical analysis revealed AB disturbances associated with general anaesthesia and pneumoperitoneum, manifested with decreased blood pH, whereas blood PvCO2, PO2 and BE were increased. A constant increase of K+ concentration was recorded in all animals during pneumoperitoneum (P<0.05), whereas iMg registered a significant increase only at T3 (P<0.05). Correlations were recorded between blood pH and Na+, iCa, iMg, as well as between Na+ and Cl¯ at different time points during anaesthesia. No correlations were noted between pH and K+ or PvCO2 and K+. In conclusion, electrolyte imbalance represents a possible complication associated with laparoscopic surgery in healthy cats. However, further studies should investigate the causes involved in K+ concentration elevation.