Abstract Background and Aims Prevailing studies indicate a correlation between elevated serum phosphate levels and an augmented incidence of cardiovascular events. In patients undergoing dialysis, hyperphosphatemia contributes to vascular and valvular calcifications. This study analyzes the interrelation of phosphate levels, inflammatory markers, and additional risk determinants in the development of carotid artery atherosclerosis in individuals receiving peritoneal dialysis (PD) versus hemodialysis (HD). Method A cohort of 39 PD and 53 HD patients were recruited, all undergoing stable renal replacement therapy (RRT) for three to thirty-six months. B-mode ultrasonography assessed the carotid artery intima-media thickness (CIMT) and detected plaque and calcification occurrences. Patients were specified as having atherosclerosis when CIMT was greater than 1 cm, and the presence of plaque was identified. Logistic regression analysis was employed to discern the connection between potential risk factors and the incidence of atherosclerosis. Results The study encompassed 92 participants, 61% undergoing HD and an average age of 53.4 years (standard deviation ± 14.5 years). The tubulo-interstitial disease was the predominant initial pathology, followed by chronic glomerulonephritis and nephroangiosclerosis. Diabetic nephropathy was identified as the etiology of end-stage renal disease (ESRD) in 23.1% of PD and 11.4% of HD subjects (p = 0.047). Notably, PD patients showed better residual renal function (RRF) (p < 0.001), urine volume over 24 hours (p < 0.001), and C-reactive protein (CRP) (p = 0.047), alongside diminished phosphate (p = 0.01), parathyroid hormone (PTH) (p < 0.05), alkaline phosphatase (p < 0.05), and albumin levels (p < 0.001) relative to their HD counterparts. Atherosclerosis prevalence was 66.3%, inclusive of the entire diabetic cohort. The incidence of atherosclerosis did not significantly diverge between PD and HD groups [56.4% vs 73.6% in HD, respectively]. Atherosclerotic patients were older (p < 0.001) and exhibited heightened phosphate levels (p = 0.012), pulse pressure (p = 0.01), and calcium index (Ci) (p = 0.034). Multiple regression analysis elucidated age, phosphate, RRF, PTH, pulse pressure, diabetes, and HD modality as autonomous factors linked to atherosclerosis. Conclusion Beyond conventional risk factors like age and diabetes, metabolic disorders arising from renal insufficiency were identified as contributing to atherosclerotic development. Multivariate analysis identified phosphate, RRF, and pulse pressure (PP) as independent atherosclerotic risk factors. The HD modality carried an elevated atherosclerotic risk compared to PD. It was thought that preserving RRF in PD patients would improve phosphate regulation and maybe even improve endothelial function, explaining the differences found.