The impact of tsetse and trypanosomosis control program conducted in Chewaka settlement station during 2005/6 was assessed through retrospective and cross sectional studies by comparing the prevalence of trypanosomosis and density of tsetse before and after the intervention within Chewaka settlement area, and the current situation at Bikiltu Didessa, where there is no tsetse control activity. A total of 830 cattle, 160 biconical traps and 160 heads of households were used for the cross sectional survey and the Buffy coat, apparent density of tsetse (fly/trap/day) and questionnaire format interview methods were employed to determine the prevalence of trypanosomosis, tsetse population density and socioeconomic status of farmers, respectively. The overall tsetse fly density in Chewaka settlement area prior to the control, 13.96 FTD, was dropped by 98.6 % to 0.2 FTD at the end of the control period. The drop in the overall mean FTD was statistically highly significant (P=0.000). The spatial distribution of tsetse had also diminished significantly; tsetse was not trapped at four sites and in the remaining three sites it exists in very low densities ranging from 0.03 to 1.10 FTDs. The mean tsetse fly density in the controlled study area, 0.2 FTD, was significantly lower (P=0.000) than the mean density in the uncontrolled stud area, 2.28 FTD. There was no difference in fly density among the six sites of Chewaka showing the uniformity of the control operation at all sites of the settlement station. The decline in the mean prevalence of bovine trypanosomosis in Chewaka from 37.5% (prior to control) to 3.1% (post control) was statistically highly significant (P=0.001). During this period the mean herd PCV had increased significantly (p=0.000) from 19.4% to 26.5 % with a slope of -0.21 and a significant negative linear correlation with prevalence of trypanosomosis (r=-1.000). The prevalence of trypanosomosis in Bikiltu, 15%, was significantly higher (P=0.000) than the prevalence in Chewaka, 3%. Animals in Bikiltu had an OR of 4.935 (2.714-8.976) Positivity as compared to animals in Chewaka implying the chance of positivity for animals in Bikiltu was about five times the chance of positivity for animals in Chewaka. There was no statistically significant difference in prevalence of trypanosomosis among the six sites of Chewaka study area and no difference was also observed (P>0.05) OR=0.614 (95%CI 0.373-1.010) among the three age groups, calves, young and adults, and between male and female animals in Bikiltu and Chewaka study areas The mean herd PCV in Chewaka, 26.5% (95% CI =26.1-27), wasrnXIrnsignificantly higher (p=0.000) than the mean herd PCV in Bikiltu, 24.4% (23.9-24.8). The mean herd PCV of sites with high prevalence of trypanosomosis in Bikiltu (Chalalaki-1, Chalalaki-2 and Burka) were significantly lower (p