Caenorhabditis elegans has been used to model aspects of a number of age-associated neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's diseases. These models have typically involved the transgenic expression of disease-associated human proteins. Here I describe my laboratory's specific experience engineering C elegans models of Alzheimer's disease, and give a general consideration of the advantages and disadvantages of these C elegans models. The type of insights that might be gained from using these (relatively) simple models are highlighted. In particular, I consider the potential these models have for uncovering common and unique fundamental toxic mechanisms underlying human neurodegenerative diseases. (c) 2006 Elsevier Inc. All rights reserved.