The Doha ministerial declaration concerning market access for non-agricultural products states that negotiations should aim, by modalities to be agreed, to reduce or as appropriate eliminate tariffs, including the reduction or elimination of tariff peaks. This study proposes a CGE assessment of the impact of various modalities of such liberalisation. Scenarios considered include the Girard's proposal (with alternative choices for the involved coefficient), the removal of tariff peaks and complete liberalisation. A special and differential treatment (SDT) for developing countries is also considered. Existing preferential trade arrangements are taken into account exhaustively, based on the MAcMap database, and tariff cuts are computed at the HS-6 product level. In addition, in order to assess properly the context in which such liberalisation is likely to take place, a pre-experiment simulation is carried out, including the MFA, China and Russia accession to the WTO, and the extension of AGOA to all sub-Saharan African countries. The impact of these scenarios is finally assessed using MIRAGE, a CGE model incorporating imperfect competition used here in its static version. The results show that liberalising non-agricultural market access is welfare improving at the world level, but that this is mainly due to the removal of tariff peaks. Crosscountry distributive impacts prove significant, and are strongly altered by granting developing countries with a SDT.