This paper deals with the impact of the Rayyan Dialect (RD) variations and the influence ofrnAmharic on the Medium of Instruction (MOI), particularly in Alamatan primary schools. Thernstudy is mainly concerned with the description of the linguistic disparities between the RD andrnStandard Tigrinya (ST) and analysis of linguistic interferences of the RD and Amharic into the ST.rnIt is also aimed at pointing out the impacts of the linguistic disparities between the two varietiesrnand the influence of Amharic on the LOI, at assessing the attitudes of the students of Alamatanrnprimary schools towards ST as LOI, and at suggesting some measures which can possibly solve orrnreduce the impacts.rnIn order to achieve these objectives, a questionnaire, interview, a writing test and personalrnclassroom observations have been used as the main data collection instruments. Six primaryrnschools have been selected using random and purposive sampling method. Grade seven studentsrnand their Tigrinya teachers have also been selected as sample subjects of the study using randomrnsampling technique. The data, therefore, have been collected through the aforementioned methodsrnfrom these subjects during schooling time. Both quantitative and descriptive methods are used inrnan integrated way to analyze the data.rnThe data have revealed that there is a gap between the RD and the MOI (ST). The linguisticrndisparities between the two varieties mainly lie at phonological, grammatical and lexical levels.rnThe data have also shown that the linguistic aspects of the RD are mainly influenced by Amharic.rnMoreover, it has also been found that there are innovations of linguistic elements in the RD.rnIt has been noticed that the disparity between the RD and the LOI as well as the influence ofrnAmharic bring about negative effect in classroom communication, on the implementation of thernST as LOI, on the students’ academic success and on the general achievement of the instructionalrnobjectives. The MOI in the primary education of Tigray is Tigrinya. However there are a largernnumber of students whose MT is entirely Amharic and face difficulty to reflect their ideas duringrnclassroom instructional process. The data have also revealed that majority of the students haverndeveloped a negative attitude towards using the ST as MOI.