The marine gastropod Nassariidae is a group of edible mud snails that are distributed worldwide. Some of the nassarid species could accumulate algal toxins that cause paralytic shellfish poisoning when being consumed. Therefore, efficient classification of nassarids is important for seafood safety, yet quite challenging because of their complex morphological diversity. In this study, an approach based on cytochrome c oxidase subunit 1—restriction fragment length polymorphism was developed to discriminate six common nassarid species, including Nassarius nodifer, Nassarius conoidalis, Nassarius sinarus, Nassarius succinctus, Nassarius variciferus, and Reticunassa festiva. Specific 709-bp fragments were polymerase chain reaction—amplified, which yielded differential digestion patterns after MspI restriction, allowing unambiguous discrimination of all six targeted species. Compared with a previously published approach for determination of nassarids using DNA barcodes, the approach developed here is much more efficient and cost saving, and will be an effective way to detect paralytic shellfish toxins—accumulating nassarids in seafood market.