This study aimed to evaluate monthly variations in testicular measurements and semen characteristics in young Tazegzawt rams. Ten yearlings rams, aged of 11 months at the beginning of the experiment were monitored over a one-year period (January-December). Body weight (BW), scrotal circumference (SC), testis diameter (TD), testis length (TL), semen characteristics and sperm kinematic parameters were recorded monthly. Significant differences were observed among months of the year for body weight, testicular measurements and semen parameters (P<0.05), whereas differences among individual rams were significant only for body weight and testicular traits. Testicular size was lowest from January to March and increased progressively from May to November reaching peak values in October and November, followed by slight decline in December. Semen volume and sperm concentration were lowest during winter and early spring, increased from late spring to autumn, and reached maximum values in December for semen volume (1.13 ml) and in October–November for sperm concentration (≈2.2 × 10⁹ spermatozoa/mL). Sperm motility showed marked seasonal variation, with minimal values in winter and early spring and maximal values (≈100%) recorded in September and October. Sperm velocity parameters peaked during late summer and autumn, indicating fast but mostly non-progressive motility. In conclusion, optimal semen quantity and quality in young Tazegzawt rams were observed from late spring through autumn, whereas reproductive performance declined during winter and early spring. These findings provide valuable information for the conservation and reproductive management of this endangered Algerian sheep breed.