Four different chemical treatments, GA3, 1-MCP, essential oils and nano-Cu, were applied immediately after harvest to Petroselinum crispum (Mill) plants. The efficacy of the above chemicals on shelf life extension of parsley stored at 5 °C and 20 °C was determined by analysing physiological and biochemical factors that determine quality standards of storage fresh parsley. Nonsprayed parsley revealed the highest loss of weight, ascorbic acid, pigments and an enhancement of CO2 production and lipid peroxidation at 5 °C and 20 °C of storage. Nano-Cu was more effective for delaying weight loss and revealed a better storage capacity. GA3, 1-MCP and essential oils sprays were more effective in ascorbic acid retention at 20 °C than at 5 °C, whereas all substances protect samples from lipid peroxidation. Essential oils were more clearly inhibitory towards both total viable counts and yeast infection. Our results suggest that GA3, 1-MCP, essential oils and Nano-Cu exert their function through different mechanisms during ripening and could provide an effective and complementary means for maintaining high-quality parsley leaves after harvest.