The AT-rich interaction domain 1A (ARID1A) are frequently mutates across a broad spectrum of cancers. The majority of ARID1A mutations are inactivating mutations and lead to loss expression of the ARID1A protein. To date, clinical applicable targeted cancer therapy based on ARID1A mutational status has not been described. With increasing number of studies reported that the ARID1A deficiency may be a novel predictive biomarker for immune checkpoint blockade (ICB) treatment. ARID1A deficiency would compromise mismatch repair pathway and increase the number of tumor-infiltrating lymphocytes, tumor mutation burden and expression of programmed cell death ligand 1 (PD-L1) in some cancers, which would suggested cooperate with ICB treatment. In this review, we summarize the relationship between ARID1A deficiency and ICB treatment including potential mechanisms, potential therapeutic combination, and the biomarker value of ARID1A deficiency.