The objective of the study was to determine the impact of age and sex on the texture and structure of fallow deer muscles, as well as to verify in what way those biological factors impacted the responsiveness of muscles to the process of massaging. The research material consisted of the fallow deer (Dama Dama) muscles: BF (m. biceps femoris), SM (m. semimembranosus), and L (m. longissimus); the age of the animals investigated was different (18 and 42 months), as was their sex (bucks and does). It was found that the muscles of 18 month old deer had the most delicate structure (the smallest muscle fibres and the thinest perimysium and endomysium), the best texture profile, and the highest responsiveness to massaging. The muscles of 42 month old deer were characterized by fibres having a big crosssection area, the thickest perimysium and endomysium; the process of massaging had the poorest impact thereon. As for the muscles of 42 month old fallow deer does, their values of structure elements and texture parameters were in between the respective values characteristic for fawns and bucks, as was their responsiveness to massaging.