Objective To observe the effects of ultrasound‑guided transverse abdominal muscle plane block (TABP) on neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in the peripheral blood of patients undergoing radical gastrectomy. Methods A total of 100 patients who were scheduled for radical gastrectomy were selected. According to the random number table method, they were randomly divided into two groups (n=50): a TAPB combined with general anesthesia group (group TAP+GA) and a general anesthesia group (group GA). Group TAP+GA and group GA underwent ultrasound‑guided TABP assisted with general anesthesia, and routine general anesthesia, respectively. Both groups were compared for operation time, anesthesia time, blood loss, and the dosages of fentanyl and remifentanil. Their counts of neutrophils, platelets and lymphocytes, NLR and PLR in the peripheral blood were recorded before and 24 h and 72 h after surgery. Their Visual Analogue Scale (VAS) scores 24 h and 48 h after operation, adverse reactions and the length of hospitalization stay were recorded. Results There were no significant differences in operation time, anesthesia time, blood loss and fentanyl dosage between the two groups. Compared with group GA, the dosage of remifentanil in group TAP+GA was significantly reduced (P<0.05). There were no statistical differences in the counts of neutrophils, platelets and lymphocytes, PLR and NLR in the peripheral blood between the two groups (P>0.05). Compared with group GA, group TAP+GA presented remarkably reduced counts of neutrophils in the peripheral blood 24 h and 72 h after operation (P<0.05). There were no statistical differences in the counts of lymphocytes and platelets and PLR between the two groups 24 h and 72 h after operation (P>0.05). No statistical difference was found in the value of NLR between the two groups 24 h after operation (P<0.05). The value of NLR in the peripheral blood of group TAP+GA was significantly lower than that in group GA 72 h after operation (P>0.05). The VAS score 24 h and 48 h after operation in group TAP +GA were lower than that in group GA (P<0.05). Postoperative nausea and vomiting were significantly reduced in group TAP+GA, compared with group GA (P<0.05). There were no statistical differences in the length of hospitalization stay, postoperative pulmonary infection, anastomotic fistula, and postoperative intestinal obstruction between the two groups (P>0.05). Conclusions Ultrasound‑guided TABP assisted general anesthesia is useful for reducing the counts of neutrophils and NLR in patients. It also improves postoperative pain, and reduces the occurrence of postoperative nausea and vomiting.