This study presents the results of determinations of Cs-137 in full-fat cow milk powder originating from four regions of Poland. The assays performed demonstrated differences in the content of Cs-137 in milk powder depending on the region. The higher content of Cs-137 was found in powdered milk samples collected from Opole (3.50 Bq/dm³). The lowest content of Cs-137 was in milk samples from Września (0.98 Bq/dm³). In powdered milk samples from Łapy and Krotoszyn the amount of Cs-137 was 2.02 and 1.11 Bq/dm³, respectively. The average content of Cs-137 in full-fat cow milk powder from all examined regions was 1.90 Bq/dm³ after reconstituting to liquid milk, and did not exceed the admissible level of Cs-137 in food.