The investigations into the emissions from light-duty vehicles have been carried out on a chassis dynamometer (NEDC test in Europe and FTP75 test in the US). Such tests do not entirely reflect the real road conditions and that is why we should analyze the correlation of the laboratory versus on-road test results. The paper presents the on-road test results obtained in an urban and extra urban cycles. For these measurements a portable SEMTECH DS analyzer by SENSORS has been used. The device is an analyzer enabling an on-line measurement of the emission gases concentration in a real driving cycle under real road conditions. The road tests were performed on road portions of several kilometers each. The obtained results were compared with the results obtained for the same vehicle during the NEDC test on a chassis dynamometer. The comparative analysis was performed including the urban and extra-urban cycles. Additionally, a comparative analysis of the on-road tests was carried out considering the road portions corresponding to the individual NEDC parts (UDC and EUDC) in terms of time and distance. Additionally, an analysis of the exhaust emissions and fuel consumption was carried out in the driving cycle with respect to the terrain quality (mountain driving). Based on the performed research the authors noted that the emission under real road conditions significantly differs from the emissions on a chassis dynamometer.