A retlospectjv~-cohort study ~'ns cal'j'jed out in NOl'theaslernrnEthiopia to aSSeSS the impact of htoalth training of primarv schoolrnteachels on health knowledge and practice of their students withrnregard to personal hygiene and the en'ironmental heallh conditionsrnof the school s .rnThe required information to .• ssess kllOIL!dge was collectedrnusing il pl'etcstcll questjonnai]'c. Observation formats wererncleve loped tc. asSuss the hygienic s t atus of the students andrnL!nironmental health situations of the schools. Focus grouprndiscussions "ere conducted wi th the trained teachers on 110" tornImprove the school health education ac[jvities. Data analysis wasrncarried out us i ng EPI-INFO version 5 and SS complltuT stat isticillrnpackages.rnThe results showed improvement in the total mean ~:nowledgernscore of teachers who recei'ed training compared to the controlrngroups If-stat. 3.4-. P:0.041 . Though the diffe"cncc was notrnstatistically signifjcailt. Students of tIle trained leachers al..;,ornshowed a hjgher mean knowledge score compared to hoth control-l -"indrncontrol-2 groups P :