In this study, granularity and its importance for traceability in seafood supply chains is studied. Granularity describes different levels of traceable units. The findings from this study show that granularity plays a key role in the implementation of seafood traceability. Implementation of a coarse granularity level is easier and cheaper than a fine granularity level, but the benefits are also lower. Fine granularity level will increase the complexity of the traceability system, and will give higher costs. A complex traceability system can affect the practical solutions and specification of the information technology systems when implementing traceability. The key is to find the preferable granularity level where the benefits exceed the costs. Consequently, the costs and potential benefits associated with implementing traceability at different granularity levels should be identified. (c) 2012 Elsevier Ltd. All rights reserved.