The goal of this research was to identify large mammals that causerndamage to sugarcane plantation and to determine the extent of therndamage; this goal was achieved. The study on the damage caused byrnlarge mammals in Wonji-Shoa Sugarcane Plantation was carried outrnfrom August 2006 to March 2007. Three sample areas were randomlyrnselected in the sugarcane plantation to collect data on sugarcane damagernand faecal droppings of the animals. Strip line transect method was usedrnto estimate hippopotamus population and total count method was usedrnto estimate warthog and grivet monkey populations. Data collected onrnpopulation estimation and faecal droppings were analysed usingrndescriptive statistic chi-square and for damage assessment T-test wasrnused. There was seasonal variation in the population of the three animalsrnin the area. The estimated hippopotamus population was 129 and 99rnduring the wet and dry seasons, which was significantly differentrn(Ï‡ 2 = 3.947, df =1, P < 0.05). The estimated warthog population was 180rnand 140 during the wet and dry seasons, which was significantlyrndifferent (Ï‡ 2 = 5.000, df = 1, P < 0.05). The estimated grivet monkeyrnpopulation was estimated 882 and 630 during the wet and dry seasons,rnwhich was significantly different (Ï‡ 2 = 42.00, df = 1, P < 0.01). Morernnumber of individuals were recorded during the wet season. The grivetrnmonkey population was most abundant and the hippopotamusrnpopulation was least abundant in the area. The sugarcane damagerncaused by hippopotamus was 2745 and 3089 stalk per ha during the wetrnand dry seasons which was significantly different (t = 16.96, df = 1, P