Introduction Colonoscopy is among the common diagnostic and therapeutic gastrointestinal interventions, which is routinely done outside the operating room. The painful nature of the procedure and patient anxiety resulting from gas insufflation propose using sedatives and analgesics during the colonoscopy procedure. The goal of this study is to compare the safety of different methods of conscious sedation in remote location anaesthesia. Materials and methods Our prospective randomised doubleblind study was conducted among 90 adult patients who were scheduled for elective colonoscopy. Patients were randomly assigned to one of the three groups: subcutaneous ketamine in conjunction with opioid, propofol in conjunction with opioid and midazolam in combination with opioids. Extra doses of opioids were administered on demand during the procedure. Heart rate, blood pressure and blood oxygen saturation were measured throughout the procedure. Adverse effects and recovery events were recorded. Results All patients tolerated the colonoscopy well. Three study groups were comparable with regard to heart rate, BP, apnoea and blood oxygen saturation. Pain score and opioid consumption were significantly lower in 'subcutaneous ketamine in conjunction with opioid' group. Patient cooperation and endoscopist satisfaction were significantly higher in the 'subcutaneous ketamine in conjunction with opioid' group. Recovery time was comparable in three groups and all patients experienced an uneventful recovery. Conclusion Subcutaneous dissociative conscious sedation, a recently reported method of conscious sedation, provides more safety and patient satisfaction in comparison with conventional methods. Subcutaneous ketamine in conjunction with opioid could be considered as a safe and efficient method of conscious sedation in remote location anaesthesia.