male The present paper deals with a study of the effect of ducting on explosions in vented enclosures. The presence of a duct was shown to increase the pressure reached in vented vessels. At the moment it is still not clear what are the main phenomena occurring in ducted-venting systems and no reliable correlations are available for the sizing of ducted vented systems. The only correlation available for gas explosions was developed by Bartknecht (1993) and assumed as a guideline in NFPA 68 (2002) while for dust explosions more correlations are available as reported in VDI 3673 (2002), in NFPA 68 (2002) and in Tamanini and Fisher (2003). This paper presents a critical review of available experimental and theoretical results on gas explosions in vessels vented through a duct that was carried out mainly to understand the role of the phenomena involved. Furthermore, the available correlations for ducted-venting of gaseous explosions of NFPA 68 (2002) and for dust explosions (Tamanini and Fisher, 2003; VDI 3673, 2002; NFPA 68, 2002) were applied to the experimental results available in the literature, to test their validity and applicability.