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. Non adherence to treatment negatively affects patient's clinical outcomes. Aim of this study to determine 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 hemodialysis admitted in previously mentioned sittingTools: four tools were used : tool I: Socio-demographic and clinical data interview questionnaire; tool Π: Clinical Dialysis Outcomes Assessment Sheet; tool III: The Illness Perception Questionnaire-Revised (IPQ-R) interview and tool VI: End Stage Renal Disease – Adherence Questionnaire (ESRD-AQ) interview sheet Results: the present study revealed that, there was statistical significant correlation 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.