A total of 12 sexually mature mixed-breed goat bucks were used in this experiment to study the effects of testosterone application (T; 25 mg IM every three days during three weeks) during the period of sexual inactivity (end of March, 26°N) on libido, odour, Sertoli cell number, seminal characteristics and serum testosterone levels. The experimental design was completely random with two groups with six bucks in each group. Reaction time was shorter (P < 0.05) in T bucks (96 ± 45 sec) than in control bucks (258 ± 44 sec). Testosterone treatment increased semen volume (1.2 ± 0.5 vs. 0.3 ± 0.03 ml for T and control bucks, respectively) and total sperm cells/ejaculate (1.32 ± 0.7 vs. 0.33 ± 0.02 x 10⁹ for T and control bucks, respectively). Buck’s odour (scale 1–5) was more intense (P < 0.05) in T bucks (1.8 ± 0.1) than control bucks (0.6 ± 0.2). Serum testosterone levels were threefold higher in T bucks (8 ng/mL) compared to control bucks (2 ng/mL) after three weeks of exogenous testosterone treatment. It was concluded that testosterone application to sexually inactive goat bucks provoke an increase in serum testosterone which in turn induces an intense sexual behaviour and the improvement of semen quality.