Tumor-associated macrophages (TAM) are a current focus in the study of the tumor microenvironment. To achieve their functionally distinct roles, macrophages undergo phenotypic polarization resulting in two major subgroups: M1 macrophages with pro-inflammatory and anti-tumor effects, and M2 macrophages with anti-inflammatory and pro-tumor effects. Of these, M2 polarization, as the main manifestation of TAMs, has been associated with a poor prognosis in various cancers and has been shown to support malignancies. Gastric carcinoma has a low early-diagnosis rate, late disease stage, and poor prognosis, with biological behavioral characteristics of easy recurrence and metastasis. Drug resistance and toxic side effects currently limit the application and effectiveness of treatments, and there is thus an urgent need to explore new therapeutic drugs and targets. This review summarizes recent progress in studies of TAM in relation to the occurrence, development, and drug resistance of gastric carcinoma, providing new ideas for clinical treatment and prognosis prediction in patients with gastric carcinoma.