In 1957 Bequaert summarized the knowledge of the non-marine mollusks of Chiapas. Thompson made several additions in various papers between 1966 and 1976 and in them described species new to science. Later, Naranjo-García et al. (2000) and Naranjo-García (2003) described two more new species. In 1993 Naranjo-García noticed that the land mollusks of Chiapas differed from the other Pacific states of Mexico and had a closer relationship with the land mollusks of Guatemala. Samples from various Chiapas sites in the National Collection of Mollusks (Colección Nacional de Moluscos) as well as material from the California Academy of Sciences were studied in order to prepare this work. The total diversity for the state of Chiapas stands at 128 species in 22 families, about 10.9% of the known fauna of the whole of Mexico. Fifty-five species have been recorded from a single locality (43% of the fauna of the state). Their present status is unknown: whether they are endemic or not, whether they are still extant or threatened, or extinct. These are issues to be resolved. Best recognized species are Lysinoe ghiesbreghti (Nyst, 1841) (which is distributed in Chiapas and Guatemala); Helicina tenuis Pfeiffer, 1849 apparently from Jalisco to Guanajuato states to southeastern México. Orthalicus princeps (Broderip in Sowerby, 1833) is widely distributed along the Gulf of Mexico, Guatemala, Belize, Honduras, El Salvador, and Costa Rica. Among the micromollusks, Lucidella lirata (Pfeiffer, 1847) is the most frequently found snail at the Montes Azules Biosphere Reserve (Southeast Selva Lacandona). Leptinaria lamellata lamellata (Potiez and Michaud, 1838) Cecilioides sp. Férussac, 1814, and Oxyloma sp. Westerlund, 1885 are new records from the same area. Recent changes in the use of the land may modify our view of the terrestrial mollusks of Chiapas state.