Cottonseed cake (CSC) is a veritable source of protein, energy and fiber for a variety of livestock species. However, it contains a deleterious polyphenolic compound, gossypol that restricts it use to ruminant feeding. Fermentation is one of the biotechnological options for reducing toxicity of many feed ingredients. This study was conducted to determine the effect of different levels of raw or fermented CSC on sperm characteristics of growing boars. Thirty (30) cross-bred (Landrace × Large White) with average weight of 7 kg, weanling boars (n = 6 per treatment) were randomly assigned to 5 dietary treatments arranged in a 2 × 2 factorial with a control within a completely randomized design (CRD). The CSC was included in diets at 0 (control), 10 and 20% (raw or fermented). Animals were fed for 12 weeks after which they were killed at average weight of 17.1 kg and the reproductive organs removed and processed for sperm characteristics. Sperm concentration was significantly (P < 0.05) higher for the control (48.50 × 10⁶/mL) than other treatments. Sperm motility for the raw CSC (68.55%) was similar to that of the control (68.01%). Boars that were fed 10% fermented CSC recorded lowest sperm motility (56.05%). Normal sperm was highest (71.34%) (P < 0.05) for the control while the lowest value was obtained at 10% fermented CSC (52.76%). Gonadal sperm reserve (GSR) was the highest (P < 0.05) for the control group (1.928 × 10⁹), while the lowest value was observed at 20% fermented CSC (0.610 × 10⁹). Boars fed raw CSC, irrespective of level, had higher GSR than those fed fermented CSC. Daily sperm production (DSP) was significantly (P < 0.05) higher for the control than 10% and 20% fermented CSC groups. Daily sperm production/gram (DSP/g) was significantly (P < 0.05) higher for 10% raw CSC (40.44 × 10⁶) compared with other treatments. This study shows that growing boars could tolerate raw CSC up to 10% in diets on a short-term basis without adverse effects on the gonadal sperm characteristics.