Public concern with intensive farming systems, particularly in the pig industry, has lead to legislation banning sow stalls and tethers and closer examination of the welfare aspects of confining the sow in a crate at parturition. In general, alternative systems have resulted in higher piglet mortality than farrowing crates. In any farrowing system, many different factors affect piglet mortality and in order for specific problems within the alternative systems to be identified and addressed, the exact causes and timings of piglet deaths need to be assessed. The objectives of this study were to determine which physical and performance characteristics of the sow and her litter influenced piglet mortality in a communal farrowing system during early lactation.