An absorbed dose of 2.7 kGy decreased the content of vitamin C by 30%. Doses below 2.0 kGy increased the content of total polyphenols. Freezing and drying affected more harshly the bioactivity of parsley than ionizing. Resistance to parsley extracts was: E. coli > S. aureus > B. cereus > S. Typhimurium. Irradiation increased the susceptibility of Gram-negatives to parsley.