Background â€“Previous studies have identified factors affecting Health Service ExtensionrnProgram implementation as well as working conditions of Health Extension Workers inrnEthiopia. Most of the studies conducted were qualitative and none of them raised the question tornwhat extent HEWs are functional and what are its determinants. The present matched caserncontrol study was conducted to evaluate risk factors for functionality of HEWs after a crosssectionalrncensusrnsurvey determination of extent of HEWs functionality.rnObjective- A study was undertaken to determine the extent of HEWs functionality and tornevaluate determinants of functionality of HEWs in East Gojjam Zone, Amharra NationalrnRegional State.rnMethod- A population based matched case control study after a cross sectional preliminaryrncensus survey was conducted in East Gojjam Zone from March to May 2009. A total of 632rnhealth extension workers were included in the cross sectional census survey. All of the (n=25)eligible cases (nonfunctional HEWs) in the zone were included in the study. Two randomlyrnselected controls [(n=50)(functional HEWs)] working from 2003 to 2008 in the same zone fromrnwhich the cases were enrolled were matched for each case for age, service year, marital statusrnand woreda of the case. Data collection instruments of separately designed self administered andrninterview based structured questionnaire were used for the cross sectional and matched caserncontrol studies respectivelyrn.rnResult- Over all non functional prevalence of HEWS in East Gojjam Zone was 4 %( n=25) Thernfinal multivariable model identified health institution support (adjusted matched odds ratiorn[Adj.mOR=40, 95% CI=4.5_360]), selection pattern [Adj.mOR=11.2, 95% CI=1.3_98.9], andrnFuture aspiration,[Adj.mOR=2.1 95% CI=1.3_57], as independent determinants of functionalityrnof HEWs after adjusting for other variables in the model.rnConclusion- In general functionality of HEWs was found to be encouraging. The majorityrn(96% n=607) were functional where as 4 %( n=25) were non-functional. HEWs are doing betterrnthe family health, personal hygiene and environmental sanitation and health education servicesrnbut communicable disease prevention and control service needs more effort. Health institutionrnsupport, selection pattern and future aspiration had been identified as independent determinantsrnof HEWs functionality. The program need to employ many qualified HRH for training,rnsupervision and support. Therefore, the real cost of scaling up HEP, including the additionalrnqualified HRH for supervision and training, should not be neglected. Moreover the need forrncareer structure for HEWs is a high concern.