In this report the results of an evaluation of the technical performance of the Dutch National Air Quality Monitoring Network in 1992 are presented. The average brute component efficiencies, i.e. a measure for the availability of measuring data, are: - for the automatically measured components [CO, NOx, O3, SO2] 96% ; - for the meteorological parameters [global radiation, temperature, wind direction, wind speed] 97% ; - for aerosols etc. [black smoke, acidifying compounds, metals, tsp] 96% ; - for the chemical composition of precipitation [i.a. acidifying compounds, heavy metals] 96%. Current Dutch legislation requires the measurement of a number of components in such way that only a minimal loss of data is tolerated. The number of stations which did not meet the legal requirements in 1992 are: two for CO[8% of the total number of stations], seven for NO2 [35%], six for SO2 [7%], two for lead aerosol [50%] and 6 for black smoke [30%].<br>