The objective of this study was to develop a measuring strategy for indoor concentrations and emission rates of particulate matter (PM) in pig fattening facilities. The rearing facility used in this study was a conventional (i.e., typical for Europe) housing system for fatteners with a fully slatted concrete floor, housing 104 pigs. Different PM fractions ranging from 0.25 to 32 µm were sampled continuously (1 minute interval) with 2 spectrometers (Grimm 1.109 spectrometers, Grimm Aerosol Technik GmbH & Co. KG, Ainring, Germany) during one fattening period starting from June 24th 2009 until October 23rd 2009. Also environmental parameters like temperature and relative humidity were sampled during the experiment. The sampling position within the animal compartment had a small significant effect on the measured PM concentration. Larger effects of the daily variations and the variation over the entire fattening period were observed. The contribution of sampling position to the variance of indoor PM concentrations was 6, 4 and 12% for PM1, PM2.5 and PM10, respectively. The effect of daily variation contributed 29, 65 and 58% to the concentration variance, while the effect of variation over the fattening period was 65, 31 and 31% for PM1, PM2.5 and PM10, respectively. Based on these conclusions, a measuring strategy for pig fattening facilities is proposed. For one fattening period, the strategy consists of 4 to 5 specific 48h-sampling periods. This measuring strategy offers the possibility to shorten significantly the total sampling time and to reduce the number of measurements without losing important PM concentration data. This strategy also allows a reconstruction of the evolution of PM concentrations over the entire fattening period.