In order to quantify the NO, NO2 and NOX, SO2, CO and PM emissions from ship traffic on the Danube, seasonal measurements (autumn, spring and summer) were performed during the period 2017-2018, using high precision mobile equipment. It is the first-time air quality monitoring actions and activities of this type have been carried out on inland waterway traffic in Romania. The selected indicators were analysed according to ISO standards in force, using chemiluminescence-based methods and non-dispersive infrared spectroscopy. The results were supplemented by measurements of ambient temperature, humidity and with observations on the number of ships transiting the fixed point, their category and the time interval. The statistical analysis is based on the daily average measurements for the monitoring points located upstream of the Danube Delta Biosphere Reserve; for Sulina monitoring area in the Danube Delta, hourly average values were used in correlation with the environmental factors. The results showed significant increases in emissions in the diurnal range, and the statistical analysis of the data showed good correlations between the power developed by ship engines and nitric gases. It has also been observed that the emission peaks can be attributed to the maximum power developed by the ships engines. Ambient temperature and air humidity showed values typical of the monitored period, and the wind direction was favourable during the three monitoring campaigns.