Inflammatory diseases are key contributors to high mortality globally and adversely affect the quality of life. Current treatments include corticosteroids or nonsteroidal anti-inflammatories that may cause systemic toxicity and biologics that may increase the risk of infection. Composite nanoparticles that bear not only the drug payload but also targeting ligands for delivery to inflammation sites at lowered systemic toxicity are established in the nanomedicine field, but their relatively large size often leads to systemic clearance. Metal-based nanoparticles with intrinsic anti-inflammatory properties represent attractive alternatives. They are not only designed to be compact for crossing biological barriers (with the nanoparticle serving as a dual carrier and drug), but also support label-free tracking of their interactions with cells. The review commences with an outline of the common inflammatory diseases, inflammatory pathways involved, and conventional drug-loaded nanoparticles for anti-inflammation. Next, the review features the emerging applications of self-therapeutic metal-based nanoparticles (e.g., gold, coper oxide, platinum, ceria, and zinc oxide) for managing inflammatory diseases in animals over the past three years, focusing on therapeutic outcomes and anti-inflammatory mechanisms. The review concludes with an outlook on the biodistribution, long-term toxicity, and clinical translation of self-therapeutic metal-based nanoparticles.