Cases of carbon monoxide (CO) poisoning are challenging for toxicology laboratories, on the other hand immediate confirmation of CO poisoning is sometimes very essential for investigating agencies. Though autopsy findings are self-sufficient for this confirmation, a laboratory validation adds more weightage. Currently, in many of our Regional Forensic Science Laboratories (RFSL), spectrophotometric analysis is used for the detection of Carboxy-haemoglobin (COHb). However, samples being susceptibile to alterations of optical state and degradation during sampling, transport and storage pose difficulties in analysis. Secondly reports from RFSL are received after much longer durations. However, hospitalbased blood gas analyzers with CO-oximetry, provide automated spectrophotometric measurement of concentration of total haemoglobin (ctHb) in blood along with that of other four haemoglobin derivatives and COHb levels, that too immediately and at a low cost. Over the background of delayed reporting from RFSL, we hereby discuss five cases of CO poisoning, confirmed with the help of hospital-based blood gas analyser.