Interim results are presented summarizing the global DNA barcoding campaign recently initiated for the Micropterigidae. This family is thought to be the sister group to all other extant Lepidoptera (Kristensen et al., 2007). Despite its potential significance for un derstanding the diversity and early evolution of the Lepidoptera, to date there is no COI data for this family available on Genbank. Preliminary phylogenetic analysis based on COI barcodes reveals the surprising potential informativeness of this marker for inferring deep relationships within the family. For example, it supports a sister relationship of the Eurasian and primarily W. Palaearctic genus Micropterix with other northern hemisphere micropterigids. As expected, DNA barcodes are also highly efficient for species-level discrimination and grouping. There are in total approximately 139 currently recognised species and subspecies of Micropterigidae, out of an estimated collected diversity that probably exceeds 230 species. Currently over 36% of described species and 21% of total inventoried species diversity has been barcoded, including over 26% of described species within Micropterix. Overall, the barcoding campaign is nearly half complete, considering an additional 63 undescribed taxa worldwide that have been sequenced, including five new Micropterix, while some countries such as New Zealand are nearing completion. We have prioritised poorly known diverse faunas such as New Caledonia and Madagascar to boost descriptive efforts. With several genera awaiting description, we may ultimately reach a larger number of undescribed than described species in this family. New results from tropical localities where micropterigids have been systematically searched for, suggest that the micropterigid fauna of many entire countries still awaits the start of an inventory. It will thus be difficult to reach a truly comprehensive barcode inventory of this family without expansion of this campaign with the help of lepidopterists in Europe and worldwide.