Thirty-two goat male kids (body weight 20 ± 2 kg; age ~5–6 months) were used to examine the effects of vinasse supplementation on growth, carcass characteristics, and blood and ruminal parameters in a completely randomized design. Kids were randomly divided into four groups: control diet without vinasse (T1) and diets containing 4 (T2), 8 (T3) and 12% (T4) of vinasse on dry matter (DM) basis. Dry matter intake (DMI) was recorded daily and animals were weighed every 21 days during the 90-day experimental period. Vinasse supplementation had no significant effect on DMI (P = 0.21), average daily gain (P = 0.61) and feed conversion ratio (P = 0.79). Adding vinasse to diets at high levels (T3 and T4) enhanced rumen pH (P = 0.03); however, it had no effect on rumen ammonia nitrogen (P = 0.62) and volatile fatty acids concentration. Plasma metabolites concentrations were not affected by treatments except the magnesium level which increased in line with the level of vinasse (P = 0.03). Vinasse supplementation induced significant reduction of the internal fat weight in the T3 and T4 groups (P = 0.02), whereas hot carcass weight (P = 0.75), carcass yield (P = 0.81), longissimus muscle (LM) area (P = 0.97), backfat thickness (P = 0.68) and LM chemical composition (crude protein (P = 0.18), ether extract (P = 0.93) and ash percent (P = 0.21)) were not affected. The obtained results may suggest that vinasse can be added into the goat kids diet up to 12% without any adverse effects on performance but with the potential to reduce the internal fat content.