The major o~iective of the study was to compare the academic achievement of bilingual andrnmonolingual groups. In the study many works have been collected regarding the effects ofrnbilingualism on students ' academic achievement and cognitive development that had been takenrnplace in western immigrant students. This sludy was held in Ethiopia in one ethnic group studentsrnof Agaws found in Sekota. Accordingly, samples of 58 bilinguals (41 female and 17 male) andrn113 monolinguals (62 female and 51 male) were taken Fom lieutenant General Hailu Kebedernjunior elementary school that was selected purposejiilly. A screening test was administered forrnthe inclusion of students in the biliilgual and monolingual groups. Altitudes of pupils andrnteachers were assessed using questionnaires. In addition, the language students ' use with eitherrnFiends or families was assessed. The result obtained in this study is consistent with previousrnresearch works and bilinguals were found to be better than their monolingual counter parts afierrna t-test comparison was made. The ANOVA result also r'! vealed that a bilingual group with highrncompetency in the two languages scored significantly a higher mean as compared with the restrnbilingual groups. J,;loreover, in the sample subjects bilinguals achieve better than monolingualrngroups on the dependent variable academic achievement. The allitude of students was found tornbe positive but teachers had a negative attitude towards Himlagna language used as medium ofrninstruction. Depending on the result, responsible bodies should encourage Himtagna motherrntongue children to follow education in their first language. In addition, attaining a secondrnlanguage without any cost ofthejirst language has higher significance for the students' cognitivernand academic growth