Nutrient contents of subadult and adult Blaptica dubia, Blaberus discoidalis and Blatta lateralis roaches, commonly used as feed source for insectivorous animals in captivity, were determined. Contents of crude protein, fat, ash, chitin, carbohydrates, calcium and phosphorus were analysed. Adults of all species contained more crude protein (602–678 g · kg⁻¹ DM > 489–547 g · kg⁻¹ DM) and ash (42–51 g · kg⁻¹ DM > 36–40 g · kg−1 DM) but less fat (145–214 g · kg⁻¹ DM < 236–363 g · kg⁻¹ DM) than subadults. Chitin content ranged 53–86 g · kg⁻¹ DM and the calcium to phosphorus ratio was 1:1.9–23.5. Amino and fatty acid profiles were also determined. Very high levels of glycine (66.4–166.2 g · kg⁻¹ DM) and alanine (81.5–118.4 g · kg⁻¹ DM) were found in all examined samples. On the other hand, the lowest amino acid levels were determined in such sulphuric amino acids as cysteine (0.5–2.1 g · kg⁻¹ DM) and methionine (4.0–17.2 g · kg⁻¹ DM). Regarding essential amino acids, very high lysine (48.6–94.0 g · kg⁻¹ DM) and valine (53.3–84.0 g · kg⁻¹ DM) levels were determined. Essential amino acid index was found at the level of 0.4–0.9. In analysed cockroaches high oleic (38.0–44.2%), linoleic (8.5–15.3%) and palmitic (21.6–26.8%) fatty acids levels were determined. The obtained results indicate that quantity of protein and lipids varied between subadult and adult cockroaches within the species, while quality of these nutrients remained stable.