Abstract Funding Acknowledgements None. Main funding source(s): Ninguno. Introduction Recently it has been shown that not all lipid risk for atherosclerosis is due to LDL cholesterol. Both, remnant and small particles have been proposed as risk factors for the first cardiovascular event and recurrences. Methods This is an observational, descriptive, prospective, single-centre, descriptive study. We set out to analyse the lipid profile on admission of patients undergoing a cardiac rehabilitation (CR) program in a tertiary hospital. In addition, we studied the association with other analytical parameters, clinical characteristics and CR results in these patients. For this purpose, data were collected from patients who completed the program between January 2022 and March 2023. We compared analytical variables at hospital admission and at the end of the program, as well as clinical and anthropometric data and stress test results. In our study we defined elevated remnants as >30 mg/dl. Results We included 170 patients who had a complete analytical profile at hospital admission. In our cohort, 80.5% were male, with a mean age of 57.9+/-9 yrs. A total of 92.5% were referred after acute coronary syndrome. There were 25.6% diabetic, 56.6% smokers and 38.1% obese patients. Patients with elevated remnants were more likely to be men (90.3 vs 79.8%, p=0.039). No differences were found in age, presence of DM, smoking, obesity or peripheral arterial disease. Functional capacity, quality of life and improvement in these parameters did not differ either. As for baseline lipid profile, it was associated with higher total Ch (190 vs 152, p=0.0), LDL Ch (109 vs 90, p=0.0), TG (227 vs 104, p=0.0) and TG/HDL ratio (6.8 vs 2.5, p=0.0) and lower HDL Ch (37 vs 45, p=0.0). 66.1% of patients with high remnants have an LDL-Ch greater than 100 mg/dl, compared with 29.6% of those with low remnants.(P=0,000). Regarding the profile at discharge, we found that 34.4% still had elevated remnants at discharge from the CR program (vs 22.2% of those without elevated remnants, P=0.000) and that 75.9% had TG/HDL greater than 2. After CR, these patients still had higher TG values (156 vs 93, p=0.000), lower HDL-C (43 vs 50, p=0.003) and higher TG/HDL ratio (4 vs 2, p=0.000), despite a greater decrease in remnants and TG/HDL in this group. Conclusions More than one third of patients undergoing a Cardiac Rehabilitation Program in our hospital have elevated cholesterol remnants. These particles predominate in male patients and initially, they have a higher prevalence of small and dense LDL and lower HDL cholesterol. In addition, the effect of the cardiac rehabilitation program on the improvement of lipid risk parameters is lower. More powerful intensive treatments are needed to improve cardiovascular risk in this population.