Knowledge of food web interactions is essential for understanding the role of carnivores in an ecosystem and designing appropriate conservation and management strategies to preserve them. These interactions can only be understood by studying carnivores' diets and obtaining comprehensive and unbiased diet data. For large carnivores—which typically rely on large herbivores as prey—the role of smaller prey species has not received attention. This study aims to quantify the contribution of small (5–50 kg) and very small (<5 kg) prey taxa in the diet of lions (Panthera leo melanochaita) in four Kenyan National Parks (NPs). We use DNA metabarcoding to achieve higher-resolution insights into prey composition, which is less biased toward large prey species compared to traditional methods, such as carcass counts. Our study identified 24 prey taxa in a total of 171 lion fecal samples. Small and very small prey taxa together contributed 18.7% out of 278 prey occurrences in all fecal samples, with comparable small prey presence (ranging from 8% to 15%) in the diet for each NP studied. This approach proved to be useful in detecting small and very small prey species in the diet of lions and can therefore be used in future research to uncover the diverse diet composition of these large carnivores. The consistent presence of smaller prey species in the diet indicates that lions generally supplement their large prey diet with smaller prey.