Immune checkpoint inhibitors, combined with anti-angiogenic agents or locoregional treatments (e.g., transarterial chemoembolization (TACE)), are expected to become standard-of-care for unresectable hepatocellular carcinoma (HCC). We measured the plasma levels of 16 soluble checkpoint proteins using multiplexed fluorescent bead-based immunoassays in patients with HCC who underwent lenvatinib (n = 24) or TACE (n = 22) treatment. In lenvatinib-treated patients, plasma levels of sCD27 (soluble cluster of differentiation 27) decreased (p = 0.040) and levels of sCD40 (p = 0.014) and sTIM-3 (p < 0.001) were increased at Week 1, while levels of sCD27 (p < 0.001) were increased significantly at Weeks 2 through 4. At Week 1 of TACE, in addition to sCD27 (p = 0.028), sCD40 (p < 0.001), and sTIM-3 (soluble T-cell immunoglobulin and mucin domain–3) (p < 0.001), levels of sHVEM (soluble herpesvirus entry mediator) (p = 0.003), sTLR-2 (soluble Toll-like receptor 2) (p = 0.009), sCD80 (p = 0.036), sCTLA-4 (soluble cytotoxic T-lymphocyte antigen 4) (p = 0.005), sGITR (soluble glucocorticoid-induced tumor necrosis factor receptor) (p = 0.030), sGITRL (soluble glucocorticoid-induced TNFR-related ligand) (p = 0.090), and sPD-L1 (soluble programmed death-ligand 1) (p = 0.070) also increased. The fold-changes in soluble checkpoint receptors and their ligands, including sCTLA-4 with sCD80/sCD86 and sPD-1 (soluble programmed cell death domain–1) with sPD-L1 were positively correlated in both the lenvatinib and TACE treatment groups. Our results suggest that there are some limited differences in immunomodulatory effects between anti-angiogenic agents and TACE. Further studies from multicenters may help to identify an effective combination therapy.