The United Nations Institute for Training and Research (UNITAR) organized a workshop in close cooperation with the UNFCCC secretariat. The workshop was held in Geneva from 30 November to 2 December 1999 with the financial support of the Government of Switzerland. It focused on the new UNFCCC reporting guidelines on annual inventories, in particular on the revised common reporting format (CRF), and on options to address challenges facing Annex I Parties with economies in transition in preparing greenhouse gas inventories. This document is intended to respond to the request of the SBSTA for a report on the workshop. The agenda of the workshop is presented in the annex to this report