Abstract Five different methods for measuring the concentrations of ambient air particles were compared in downtown and suburban areas of a medium sized Northern city in winter and spring: namely total suspended particulates (TSP) measured by HiVol and dichotomous samplers, particles < 10 μm (PM 10) measured with a PM 10 impactor and a dichotomous sampler, black smoke (BS) measured by the OECD method, and size fractionated particles measured by an electrical aerosol spectrometer (EAS). The BS/PM ratio decreased gradually from winter to spring. The TSP and PM 10 measurements correlated highly with each other. All measures of inhalable particles BS, PM 10 and EAS-PM 1.0−1.0 correlated highly with each other. BS concentrations correlate best with the EAS-PM 3.2 fraction. Principal components analysis revealed that the measured BS and TSP come from different sources. The TSP and PM 10 measured with the dichotomous sampler showed consistently lower values than the other methods.