Background: In haemodialysis patients; illness perception play a role in influencing a person's behavior, especially in terms of adherence to therapeutic regimen, this means patient perception directly or indirectly influences treatment adherence and clinical outcomes . Aim of this study todetermine the relationship between illness perceptions, treatment adherence and clinical outcomes among patients on maintenance hemodialysis.Research design: A descriptive correlational research design was used to conduct this study. Settings: This study was conducted at the hemodialysis unit of the Damanhour general hospital, Elbeheira Governorate. Subjects:  A convenience sample of 130 patients on maintenance hemodialysisadmitted in previously mentioned sittingTools: four tools were used : tool I: Socio-demographic and clinical data structured  interview; tool Π:Clinical Dialysis Outcomes Assessment; tool III: The Illness Perception Questionnaire-Revised (IPQ-R) interview and tool IV:  End Stage Renal Disease – Adherence Questionnaire (ESRD-AQ) interview Results: the present study revealed that, more than three quarters (80.0%) of studied patients had moderate illness perception and less than one fifth (19.2%) had high illness perception , more than half (53.1 %) of studied patients  had  overall good adherence , there was statistical significant relation between mean of  systolic blood pressure pre- post dialysis and levels  of overall illness perception, and  a  highly significant negative correlation between overall adherence to the therapeutic regimen and clinical outcomes.Conclusion: more than three quarters of studied patients had moderate illness perception and more than half of studied patients  had  overall good adherence. Recommendations: Illustrated booklets, handouts, and audiovisual materials regarding therapeutic regimen instructions and replicating of the study using a larger sample size to ensure generalizability of results.