Chronic illness has been documented to have negative psychological effects on individuals. The purpose of this study was to examine if elevated levels of stress, anxiety and depression exist in patients suffering from chronic cardiac illness. This study also aimed to examine if differences in levels of stress, anxiety, and depression exists in two different subsets of patients. The sample for the study was gathered from Our Lady's Hospital, Navan. The control group sample was gathered from the general public. Data was gathered from 3 subsets in total. The first subset (n = 25) was patients with Atrial Fibrillation / Myocardial Infarction who were attending a cardiac rehabilitation group with psychological support. The second subset (n = 25) were patients attending an anti-coagulant PT (prothrombin) clinic in the outpatient department of Our Lady's Hospital, Navan. The third subset (n = 25) was the control group, who were not suffering from a chronic illness. The design of this study was a across sectional between group comparison. Statistical analysis was by use of ANOVA and MANCOVA to analyse the data. There was a significant difference identified between stress levels in the control group compared to the two subset groups of patients. (F [2, 72] = 9.477, p< .001). No significant differences were identified between the different subsets of patients.