The aim of the work was to evaluate the retention of amino acids in white cauliflower florets and the quality of protein. The investigation concerned the raw material and florets prepared for consumption, both from the fresh material and from two types of frozen product: one obtained using the traditional method (blanching–freezing–refrigerated storage–cooking); and the other using a modified method (cooking–freezing–refrigerated storage–microwave defrosting and heating). In 100 g of the raw material the total amino acid content was 1674 mg; the content was significantly higher only in the modified frozen product. The amino acid content found in 16 g N did not significantly differ between the investigated samples, varying in the range of 79.76–87.53 g. Essential amino acids constituted 43–45%. In all the samples the limiting amino acids were cystine with methionine, with glutamic and aspartic acids dominating.