In addressing land degradation problems a number of interventions have been made in Ethiopia, gully rehabilitation is one of such measures. But so far, the economic value of gully rehabilitation from the point of view of estimating the opportunity cost has not been undertaken. Hence this study attempted to develop methods of valuation of gully rehabilitation, by formulating a technique in valuing the gully rehabilitation work in monetary terms, in a way that incorporates all the major costs and returns of the gully and its rehabilitation. The study also tried to construct scenarios to gain opportunity cost information about the future. Four model-rehabilitated gullies (Eshim Wofena, Worken Gashajagrie, Worken Adura, Tsegur Eyesus) in Farta woreda, South Gonder, Ethiopia, were studied to economically quantify rehabilitation projects under a range of techniques. The data used were obtained from a physical data survey and supplemented with secondary sources. Data were obtained on all the major costs like gully soil loss area with yield loss cost, and establishment cost. The major returns were nutrient accumulation with local price of fertilizer, tree volume (crown and wood) with local tree volume benefit after felling, and standing plant biomass with carbon sequestration benefit. The total costs and return values of the data were compared monetarily through opportunity cost computation. The results of the study indicate that at current stage by taking the smallest and largest gullies (Worken Adura and Eshim Wofena), the gully benefits Birr 208,874.6 to 406,489.26 respectively accounting the sustainable carbon sequestration and nutrient components. While the short-range ideal gain which considers tree volume gain besides sustainable components, for the same gullies reaches from Birr 1,126,924.22 to 5,057,656.48. However the cost side attains the same amount in both cases. Under optimal management on the year 2021 the cost side is estimated to be in between Birr 263,869.74 to 470,727.18 while the benefit was between Birr 29,644,486.24 and 116,368,436.40 for Worken Adura and Worken Gashajagrie gullies respectively. The cost or benefit variation between gullies depends on the specific gully cross sectional area, tree number and species diversity type etc. The high monetary return with a very meager cost, in this regard, establishing gully rehabilitation is a proficient investment that is worth spending. Hence the study reminding the complexity of valuation methodology, calls for major multidisciplinary and participatory research efforts in order to make such study results more useful and the results more credible.rnKey Words- Gully rehabilitation, Economic value, Scenario, Opportunity cost, Sustainable and Ideal benefit