Vermicelli has long existed in southern Fujian's Zhangzhou, Quanzhou, and Xiamen, where toppings range from pig liver and preserved radish to fried dough sticks and chicken legs. These toppings serve as both a clue to the dish's origins and a measure of its success. The snack reportedly arrived with early Hokkien immigrants from Zhangzhou and Quanzhou; Taiwan's island geography made readily available oysters a natural addition to the noodles.

Historical evidence appears as early as 1940 during the Japanese colonial period. Artist Tateishi Tetsuomi's illustrations in Folk Taiwan depicted food stalls at Yongle Market, with accompanying text identifying oyster geng—Oyster Vermicelli—among the offerings.

Taiwan's oyster cultivation spans the southwestern coast from Changhua County southward. While available year-round, summer brings abundant plankton that makes oysters plumpest and Oyster Vermicelli at its finest.

North-South Taste Divide

Taiwan's north and south maintain distinctly different vermicelli preferences. Southern versions, called mī-suànn-kôo, lean sweeter with heavier starch thickening; northern Taiwan relies on bonito flakes for a lighter broth base. Toppings vary regionally as well—southern vendors offer diverse additions like meat chunks and fish paste, while northern stalls focus primarily on oysters and intestines. The outlying Penghu islands favor clear vermicelli with oysters.

Most Taiwanese oyster vermicelli uses red vermicelli noodles. After cooking and draining, vendors ladle on oysters and fresh garlic paste, then add dried shiitake mushrooms and dried shrimp before finishing with cilantro. Devoted eaters track down bowls by following the distinctive aroma of garlic and cilantro.

In regions where fresh seafood proves harder to source, meat thick soup or intestines substitute for oysters—which explains why oyster vermicelli stalls typically offer intestine and meat thick soup versions as well. Economic prosperity and modern transportation now ensure that even Taiwan's inland areas can enjoy fresh, flavorful oyster vermicelli.