Gastric dysplasia is a well-known precancerous lesion. Though the diagnosis of gastric low grade dysplasia (LGD) is generally made from endoscopic forceps biopsy (EFB), the accuracy is doubtful after numerous EFB-proven gastric LGD were upgraded to gastric high grade dysplasia (HGD) or even carcinoma (CA) by further diagnostic test with the procedure of endoscopic resection (ER). We aimed to evaluate the upgraded diagnosis rate (UDR) and the risk factors by ER in EFB-proven gastric LGD lesions. Two investigators independently searched studies reporting the UDR by ER in EFB-proven gastric LGD lesions from databases and analyzed the overall UDR, HGD-UDR and CA-UDR. The pooled UDR by ER in EFB-proven gastric LGD lesions was 25.0% (95% CI, 20.2%-29.8%), made up of HGD-UDR and CA-UDR by rates of 16.7% (95% CI, 12.8%-20.6%) and 6.9% (95% CI, 4.2%-9.6%) respectively. Lesion size larger than 2 cm, surface with depression and nodularity under endoscopic examinations were the major risk factors associated with UDR. In conclusion, one quarter of EFB-proven gastric LGD lesions will be diagnosed as advanced lesions, including gastric HGD (16.7%) and gastric CA (6.9%) by ER. The diagnosis of those LGD lesions with an endoscopic diameter larger than 2cm, and depressed or nodular surface are more likely to be upgraded after ER.