Informal sector foods are considered a vector of unhealthy fatty acids linked to noncommunicable diseases (NCD). This study is aimed at investigating the hazardous and nutritional fatty acids and sterols in commonly consumed ready-to-eat (RTE) street foods (n=108) in Sri Lanka using modified and validated AOAC and AOCS test methods. Significant variations (p<0.05) were detected in fatty acid composition among different foods. A comparatively higher fat content (>17.5 g/100 g) was observed in 95% of pastry samples, while 51.5% of total foods exceeded the national threshold limit (8 g/100 g) for children. Saturated fatty acid (SFA) was higher than 1.5 g/100 g in 93% of food. SFA was more predominant than polyunsaturated fatty acids (PUFA) in all foods. The most prominent SFA was palmitic acid. Oleic acid was the major unsaturated fatty acid. Total trans fatty acids detected in all foods were in the range of 0.12-1.60 g/100 g. The PUFA/SFA ratios of all analysed street foods (0.16-0.28) were less than the recommended PUFA/SFA ratio of ≥0.4. Omega-6/omega-3 fatty acid ratios of all food were 18 : 1-24 : 1, which is higher than the WHO-recommended ratio of 4 : 1-5 : 1. Mean atherogenicity and thrombogenicity indices were 0.80-1.63 and 1.47-2.76, respectively. The essential fatty acids of α-linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid were less than the required nutritional intake. The most prominent phytosterol is the β-sitosterol in all foods, and total phytosterols were 3.29-136.65 mg/serving. Cholesterol was in the range of 0.36 to 256.85 mg/serving. These results suggest that consumption of these selected street foods may aid in increasing the risks of NCDs in consumers, and findings emphasise the urgency of improving the nutritional quality of street foods by continuously monitoring and regulating the present culinary practices. This study is the first to report a comprehensive fatty acid composition, including sterols, in RTE foods.