A small, recent collection of reptiles from Paksé and from Xépian National Biodiversity and Conservation Area, Champasak Province, southern Laos, contains the second Laotian specimen of the Indochinese spitting Cobra, Naja siamensis (Laurenti, 1768). This species was previously known from this country from a single specimen observed in Savannakhet Province, in the north of Central Laos. This second specimen, the first one to have been preserved for this country, is described in details. It shows a pattern slightly different from the first Laotian specimen. This new specimen confirms the occurrence of this medically important species in different parts of the Mekong valley. A juvenile specimen of Oligodon taeniatus (Günther, 1861) proves the first voucher specimen of this species recorded from Laos. Specimens previously cited from the Vientiane area as Oligodon taeniatus proved to belong either to Oligodon mouhoti (Boulenger, 1914) or to an unidentified taxon. The list of snake species known from Champasak Province is updated; it currently includes 37 snake species.