Background: Embolization is a well-established treatment modality for liver cancer. However, traditional embolization agents are limited by inefficient delivery and aggregation in blood vessels. Novel shear-thinning hydrogels have been developed to address the need for safer and more effective local delivery of embolic agents and therapeutics. Objective: To evaluate the efficacy of novel embolic agents such as a drug-eluting shear thinning hydrogel (DESTH) using a human-relevant in vitro model that recapitulates human tumor capillary networks. Methods: A vascularized human liver-tumor-on-a-chip model was developed to assess embolic agent performance. The effects of DESTH on tumor cell viability, gene expression, vasculature morphology, and cytokine responses were evaluated. To study the effects of embolization on microvasculature morphology independent of the chemotherapy compound, we assessed the effect of different embolic agents on the vascular tumor microenvironment under flow conditions. Results: DESTH treatment induced tumor cell death, downregulated the expression of Epithelial Cell Adhesion Molecules (EpCAM) in HepG2, increased levels of cytokines such as Interleukin-4 (IL-4), Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF), and Vascular Endothelial Growth Factor (VEGF), and decreased albumin secretion. Furthermore, different embolic agents exert distinct effects on microvascular morphology, with shear-thinning hydrogel (STH) causing complete regression of the microvascular networks. Conclusion: This vascularized liver tumor-on-a-chip model enables human-relevant, real-time assessment of embolic agent efficacy and vascular response, paving the way for the development of novel, effective embolization therapies for liver cancer.