The objective of this study was to evaluate the effect of two spineless cactus (Nopalea cochenillifera) levels (250 g/kg or 550 g/kg) as an exclusive source of water on the performance, serum biochemistry, blood count, ingestive behaviour, carcass characteristics and non-carcass components of confined goats. Forty Anglo-Nubian castrated male goats were used, housed in individual pens and distributed in a 2 × 2 + 1 factorial design of spineless cactus factor (250 g/kg or 550 g/kg of spineless cactus in the dry matter of the diet) and water factor (with or without access to drinking water) and control diet (without spineless cactus and with access to drinking water). The restriction on drinking water did not influence (P > 0.05) the average daily gain, carcass weight or serum biochemistry of the goats. The inclusion of spineless cactus increased (P < 0.05) the average daily gain, body weight at slaughter and carcass weight of the goats and reduced (P < 0.05) animal drinking water intake. Goats fed 250 g/kg of spineless cactus in their diet chewed more (P < 0.05), drank more water (P < 0.05) and had greater gastrointestinal tract contents (P < 0.05) than goats fed 550 g/kg of spineless cactus in the diet. Spineless cactus from 250 g/kg can be used as an exclusive source of water in the diets of confined goats. •Spineless cactus was tested as an exclusive source of water for goats.•Including 250 g/kg of spineless cactus can be used as an exclusive source of water.•Drinking water deprivation does not interfere with goat performance.•We recommend including 250 g/kg of spineless cactus in confined goats' diets.