Under the study presented, it was determined the effect of packing spinach in a modified atmosphere and using a packaging film of an oxygen permeability of 1900 and 3000 cm³/m²/24 h·bar on changes in nitrates(III) and (V) in the spinach packed during its 12-day storage at 4 ºC. The content of nitrate(V) was high in both the raw material and all the analyzed samples packed in a modified atmosphere; it ranged from 937 to 1212 mg/kg f.w., though, it did not exceed the admissible limits. A high content of nitrates(III) was recorded in the samples stored for 12 days and packed in air and in the atmosphere with 10 % O₂, 10 % CO₂, and 80 % N₂. The samples wrapped with the film of a permeability of 3000 cm³/m²/24 h·bar (105 and 221 mg/kg, respectively) had a higher content of nitrates(III), whereas the samples wrapped with the film of a permeability of 1900 cm³/m²/24 h·bar (77 and 124 mg/kg, respectively) had lower contents of nitrates(III). The samples packed in the air and in the modified atmosphere with 10 % O₂, 10 % CO₂ and 80 % N₂ were characterized by the worst sensory quality, irrespective of the applied packing material. It was found that the samples packed in the atmosphere containing 20 % O₂, 5 % CO₂, 75 % N₂ and 20 % O₂, 25 % CO₂, 55 % N₂ had the best sensory quality and the lowest increase in the contents of nitrates(III) during their storage.