The common bushbuck (Tragelaphus scriptus decula) is a widely distributed antelope species in Africa that utilises a variety of habitat types. A study was conducted on the population status and diurnal activity pattern of T. s. decula in Maze National Park, Ethiopia, from January to July 2020 during the wet and dry seasons. Data were collected using randomly sampled blocks covering a total area of 34 km². The data were analysed using descriptive statistics and compared with Chi-square and one-way ANOVA tests. The average population size throughout both the wet and the dry season was 21 ± 8, of which 10.5 ± 3.5, 4.0 ± 2.0 and 6.5 ± 2.5 were adults, subadults and juveniles. There was a significant difference (χ² = 3.4, df = 4, p < 0.05) in the T. s. decula population between the two seasons. The sex ratio of adult males to adult females was 0.56:1 and 0.75:1 in the dry and the wet seasons, respectively, indicating a population predominated by females. The mean group size was x̄ = 2.16 and 2.00 for the dry and wet seasons, respectively. The riverine forest had the greatest number of individuals and hence highest density and population distribution per square kilometre; however, distribution between the habitats did not vary significantly (F = 2.71, df = 4, p = 0.16). The overall density of the population was very low in the sampled blocks, with the population density not exceeding one per 1.7 km². The dominant activity pattern of T. s. decula was feeding followed by resting and running/fighting. Even though its population was predominantly female, a good indicator for future breeding success, the low numbers and density of common T. s. decula due to the high impact of illegal hunting and predation, especially of subadults, indicates a vulnerable population requiring enhanced conservation efforts.