The objective of this study was to establish if immunocastration, together with different levels of supplementary feeding, influenced the chemical composition and organoleptic properties of fallow deer meat. The meat from non-castrated fallow deer had higher protein, and lower moisture, contents than immunocastrates. The total collagen and soluble collagen, and overall flavour intensity, was affected by the interaction of castration status and nutritional level. Meat from immunocastrates showed improved tenderness and juiciness scores, whilst those animals receiving the low feed level had higher scores for grassy aroma. Immunocastration improved important sensory properties of fallow deer meat, and may be considered as an appropriate husbandry tool for farmed fallow deer venison production.