Although the fruit of the carob tree (Ceratonia siliqua L. Fabaceae) is nutritious and widely available in Turkey, especially in West and South Anatolia, much remains to be learned about its nutrient composition. The main goal of our study was to determine if there are differences in the content of certain nutrients in commercially-prepared carob flour (CPCP) and domestic or home-prepared carob powder (HPCP). Sucrose was the main sugar in CPCP and HPCP. Total protein was 40% lower in CPCP than HPCP due mainly to decreases in the content of several essential amino acids. However, except for lysine in CPCP, HPCP and CPCP compared favourably to a WHO protein standard. There were large differences in terms of their content of the two essential fatty acids, linoleic and alpha-linolenic acid, and the linoleic acid/alpha-linolenic acid ratio was 3.6 for CPCP, and 6.1 for HPCP. Manganese and iron were 2.5-fold higher in HPCP than CPCP. This study demonstrates that carob flour prepared in either the household or industrially is a good source of many, but not all essential nutrients, and that commercial processing of carob fruit into flour seems to affect its content of several important nutrients.