Compared with strain A44, male and female ducks of strain A55 showed significantly higher body weights at 7 weeks of rearing. They did not differ only in shank length and breast muscle thickness. Dressing percentage and percentage of tissue components were similar in both strains. Only the percentage of skin with subcutaneous fat and weight of abdominal fat were lower in A55, which is a favourable result. The weights of breast and leg muscles were found to be positively and significantly correlated with the lengths of trunk with neck, trunk, sternum and shank. The percentage of skin with subcutaneous fat combined with abdominal fat was significantly and negatively correlated with trunk and sternum length and with chest and shank circumference. Trunk and sternum length can be used in selection for high weight of breast and leg muscles and decreased fatness, while shank length can be employed in the selection for decreased fatness. pH₁₅ and pH₂₄ values in strains A44 and A55 were similar to those found in other studies. The water holding capacity of breast and leg muscles was high and higher in A55, whereas the water content of muscles was similar in both strains. Percentages of protein and ash were higher in breast muscles and those of fat in leg muscles. In other Polish and foreign studies the proportions of protein, fat and ash in the muscles were greater. The meat quality of A55 ducks was superior to that of A44 ducks.