Purpose: This article investigates the impact of the open archive initiative on the document supply of grey literature. Approach: The article is based on a comparative survey of five major institutions: The British Library (UK), the CISTI (Canada), INIST-CNRS (France), the KISTI (South-Korea) and the TIB Hannover (Germany). Findings: All major document suppliers are more or less deeply involved in the open archive movement, and this involvement has an obvious impact on the policy of acquisition, archiving and supply of grey literature (dissertations, reports, conferences etc.). Originality: Even if the impact of increased access to digital resources on document supply is relatively well documented, little is known about the specific effect on grey literature, especially in the OA environment. This study provides some evidence concerning this effect.