Accurate prediction of groutability of a soil mass by permeation has always been complicated sincernthe effective penetrability of grout in to voids is a function of several interrelated parametersrncontributed from the physical and mechanical properties of a medium to be grouted, the nature ofrngrout used, efficiency of groutability assessment techniques adopted, and other factors related torngrouting design and operation. Special concern on groutability sounds most relevant while dealingrnwith grouting of medium with very fine fractures and/or porosity. Various researchers so far haverndeveloped relations or techniques by which the permeation groutability of a soil mass can be assessed.rnThe present research has attempted application of those selected techniques for preliminaryrnpermeation groutability assessment on volcano-clastic sediments (particularly on unwelded tuff andrnvolcanic-breccia deposits).rnThe study was conducted as a case study at Kesem dam and irrigation project located in Afar regionalrnstate of Ethiopia. The proposed dam site abutments geology comprises of thin to thickly bedded,rnpervious and very weak un-welded tuff and volcanic breccia deposits which occur sandwiched inrnbetween competent rock units. Though intensive permeation grouting was implemented at both thernabutments, it did not bring satisfactory result on those layers. The present research therefore has dealtrnabout permeation groutability evaluation of un-welded tuff and volcanic breccia deposits composingrnabutments of the Kesem dam project.rnThe research has followed two basic approaches for evaluation of permeation groutability: one isrnapplying soil permeation groutability assessment techniques, and second is based on insitu conditionrnmanifestations. For the former approach, grain size distribution, permeability and porosity of mediarnwere studied and used in the analysis. In the later case, the actual foundation permeation groutingrnresponse was examined on the basis of evaluation of project records kept for previous actual and testrngrouting that were conducted in the study area. Besides, indications of an in-situ chemical permeationrngrouting test (attempted during the present research using sodium silicate grout) were used.rnThe evaluations have led to identification of suitable grout types viable for effective permeation in tornporespaces in unwelded tuff and volcanic breccia deposits studied. Effective permeation range of therndeposits has fallen within chemical grout zone, colloidal (silicate) solution or any less viscousrnsolutions. Moreover, the dependability of the current research approach, for use on preliminaryrnpermeation groutability assessment on Volcanoclastic sediments, was verified since results from bothrnapproaches end up with good agreement.rnFinally, on the basis of findings of the research, recommendations are forwarded to help on the onrngoing efforts to look for solutions against encountered geotechnical problems of the site.