Nanomaterials offer transformative potential in the treatment of inflammation and cancer—two pathologies intricately linked through shared mechanisms such as oxidative stress, cytokine dysregulation, and immune cell activation. Nanomaterials properties influence cellular uptake, immune recognition, cytokine modulation (IL-6, TNF-α), oxidative stress responses, and tissue-specific accumulation, especially within inflamed or tumor microenvironments.By leveraging properties including size, shape, surface charge, and composition, NPs can exploit the enhanced permeability and retention (EPR) effect, modulate immune responses, and deliver therapeutics with high specificity and reduced systemic toxicity.Distinctions between core composition and surface functionalization such as PEGylation and ligand conjugation (e.g. folate, anti-EGFR antibodies)are clarified, highlighting their combined roles in targeting specificity, immune evasion, and therapeutic outcomes. Size and surface charge further influence biodistribution, cellular uptake, and cytokine production, particularly IL-6 and TNF-α, which are pivotal in both chronic inflammation and tumor progression. The influence of synthesis parameters on nanoparticle behaviour in particle size, crystallinity, and surface reactivityis linked to their biomedical performance and safety profiles. Continued innovations in nanoparticle design, synthesis, and functional integration hold promise for the next generation of onco-inflammatory therapeutics.