Background: The present study investigated the effect of the Middle East dust storm episodes on the concentration and composition of PM10 during April to September 2013 in Sanandaj City, western Iran.Methods: Sampling was once every six days, and on dusty days using an Omni air sampler. The PM10 sample was collected on polytetrafluoroethylene filters. Average of 24 h values of PM10 mass concentrations was determined. Half of each sample filter and blank filter was ana-lyzed for water -soluble ions and the other half was digested for metal analysis.Results: The average PM10 concentration was 160.63 mg/m3. The lowest and highest concen-trations of PM10 were in May and June respectively. The average PM10 concentration during the non-dusty days was 96.88 (mg /m3). Nevertheless, it increased by 4.8 times during the dusty days. Ca2+, Cl-, NO3-, and Na+ accounted for 71% of total water-soluble ions on the dusty days. During the dusty days, the dominant elements in PM10 were Na, Ca, Mg, Al, and Fe con-tributing to 95.72% of total measured metals. The correlation coefficient and enrichment factor analysis have shown that on dusty days, Al, Ca, Fe, K, Mg, Na, Sr, and V were the elements with the crustal sources.Conclusions: Concentrations of PM10 during dusty days were considerably higher than that during non-dusty days. In addition, concentrations of water-soluble ions and metals were also higher during dusty days.