A rare example of an organised industrial workshop is reported, from the environs of the ethnic Lamet village of Saphim in Luang Namtha Province in NW Lao PDR. The archaeological site contains the remains of seven sub-circular furnaces in a distinct linear arrangement. Two furnaces were excavated, one of which was largely complete and provided evidence for a forced blast, multiple use, slag-tapping iron smelting operation. Six thermoluminesence dates derived from wall fragments provide a date range from 621±270 to 1181±170 AD, indicating that the workshop relates to production in the historic pre-European contact period. The organised layout of the furnaces is suggestive of either simultaneous production or a production sequence, rather than the distribution expected of chronologically superposed production within dating resolution limits. A multi-furnace workshop level of supply was probably in excess of local demand, and thus contemporary regional comparisons for social contexts of iron production and exchange networks are explored.