The SG 2000 extension project has been disseminating improved maize technologies, amongrnothers, to achieve its objective of improving farm productivity and thereby increasing foodrngrain production. However, the SG 2000 project may not be special to weakness andrnconstraints that the previous extension approaches were faced with. Thus, this thesis hasrnattempted to identify determinants of extension participation, and to evaluate the impact ofrnthe SG 2000 extension project on maize production by examining the level of awareness,rnadoption, and the increment in productivity and profitability attained using the improvedrnmaize production in the Bako area. The Probit model and the Two-Stage SwitchingrnRegression approach were employed in the analysis using data collected from 225 samplernfarm households.rn~rnIt has been found out that proximity to the main road, number of oxen owned, total farm sizernowned, education level of the household head and availability of credit for down paymentrnsignificantly affected farms decision to participate in the SG 2000 extension activities significantly high number of both the extension participant and non- participant sample rnfarmers have been aware of the improved maize technologies. However, while almost all thernsample extension participating farmers adopted the improved maize technologies, only 10%rnof the sample non-extension participating farmers adopted. The analysis showed that usingrnthe improved maize technologies is much more productive as indicated by the higherrnelasticity coefficients and the marginal products of the inputs. The increment in productivityrn(gross benefit) resulted from the extension program has been estimated to be 37. 25 quintalsrnof grain maize per hectare. Considering different scenarios of cost for the improved practicesrnthe net benefit for the SG ranges from 726.46 to 1267.48 Birr per hectare, and accordinglyrnthe MRR ranges from 36% to 213%. On the other hand, the net benefit for the NSG from therntraditional practices is only 385.60 Birr per hectare.rnNevertheless, many technical and policy problems have been identified affecting thernsustainability of the adoption and the incremental productivity of the improved maizerntechnologies. Therefore, the use of the improved maize technologies and the net benefitrnexhibited by the adopters may be for the short-run and lo may be limited to benefit only fewrnfarmers. Thus, the challenge remains with how to accelerate the adoption and maintain the productivity level of the improved maize technologies on a sustainable base. In this regard,rnsubsidizing and facilitating credit services, output price support, encouraging intra-regionalrntrade, improving input supply, promoting the development of infrastructure and encouragingrnfurther research to develop streams of improved seeds are suggested.