The research was aimed at evaluating the nutritional value of mechanically separated meat (MSM) of two different the poultry species and to compare it with the corresponding characteristics of hand-separated meat. The research was conducted on chicken and geese meat obtained by pressure separation (with a SIMO Meat Separator), in which muscle tissue is ground along with bones, cartilage, and sinews. The raw material for the production of MSM included backs, wings, necks, and trunks (except for breast muscles) of broiler chickens and slaughter geese, as well as whole goose carcasses that did not meet commercial standards. Samples were collected during 20 production cycles. The examination was conducted on chicken and goose MSM, as well as on hand-separated chicken and goose meat, which consisted of breast and thigh muscle samples. Hand-separated muscles were the control. The total protein content was determined by the Kjeldahl method, the fat content by the Soxhlet method, the water content by desiccation at 105°C, the calcium content by flame atomic absorption spectrometry with a Varian Spectra AA 2807S spectrometer, and the phosphorus content by spectrophotometry with a Shimadzu UV-1800 spectrophotometer. Fatty acid composition was determined by gas chromatography with a Varian CP 3800 chromatograph. The amino acid profile of mineralized proteins was determined with an AAA 400 amino acid analyser (Ingos Praha). The biological value of proteins was determined on the basis of their amino acid composition by calculating the chemical score (CS) and the essential amino acid index (EAAI). The significance of differences between the characteristics under analysis was evaluated by Tukey’s test at p ≤ 0.05. The chemical composition of MSM of chickens and geese showed significant differences. Chicken MSM contained significantly more proteins, water, and calcium, but less fat than goose MSM. Hand-separated meat had significantly higher contents of proteins and water, but lower contents of fat and calcium than both kinds of MSM. The two kinds of MSM did not differ significantly in their phosphorus content, which however was significantly lower (by 50%) than that in hand-separated meat. The content of most amino acids in proteins was significantly higher in chicken MSM than in goose MSM. The content of amino acids in both kinds of MSM was significantly lower than in hand-separated meat. This was also true about exogenous amino acids, which are particularly important for the biological value of proteins. Compared with the amino acid composition of model proteins, the proportion of exogenous amino acids in MSM was unfavourable from the point of view of human nutritional needs. Amino acids that limited (CS) the absorption of proteins were sulphur amino acids in the case of chicken meat (both mechanically and hand-separated) and aromatic amino acids in the case of goose meat. The content of saturated fatty acids (SFA) differed significantly between MSM and hand-separated meat, as well as between chicken and goose MSM. The same pattern was observed for polyunsaturated fatty acids (PUFA). Unlike mechanically separated and hand-separated goose meat, chicken and goose MSM differed significantly in their monounsaturated fatty acid (MUFA) content. Our own research revealed an unfavourable proportion of PUFA n-6 to PUFA n-3 in chicken MSM (18:1) and confirmed a high nutritional value of fat in goose MSM (8:1) and in hand-separated goose meat (8-9:1). Fat in chicken and goose MSM differed significantly in the proportions of SFA to MUFA and to PUFA The content of monounsaturated fatty acids was twice as high as that of saturated fatty acids both in goose meat and in MSM produced from it. Our own research demonstrated that the proportion of unsaturated fatty acids (UFA) to saturated fatty acids (SFA) in goose MSM is better than that in chicken MSM. The nutritional value of mechanically separated poultry meat is considerably lower than that of hand-separated poultry meat. An excessive use of mechanically separated poultry meat in the production of meat products may significantly reduce their biological value.