A study aiming to measure ammonia emissions from light duty vehicles has been performed in the Vehicle Emission Laboratory at the European Commission Joint Research Centre, Ispra, Italy. Ammonia, known for being toxic and dangerous for the environment, also contributes to the formation of particulate matter that has been related with adverse health and environmental effects. Nine modern light duty vehicles tested over the New European Driving Cycle showed that ammonia emissions are considerable for gasoline and ethanol flexi-fuel vehicles and also for one diesel vehicle equipped with a selective catalytic reduction system, ranging from 4 mg/km to 70 mg/km. Real-time ammonia emission profiles were monitored at the tailpipe by a High Resolution Fourier Transform Infrared spectrometer during tests at 22 and/or −7 °C. Ammonia emissions are thoroughly discussed and compared to those of its precursors, CO and NO, and other regulated compounds. •All studied vehicles emitted NH3 when tested over the NEDC at 22 and −7 °C.•NH3 emissions from Euro 5–6 vehicles are similar to those reported a decade ago.•Vehicular emissions of NH3 and CO presented good correlation.•Emission of NH3 depends on ambient temperature and NOx emission control.