Technical Abstract: Because of their relative abundance, distribution across the genome, hypervariability and co-dominance, microsatellites, or simple sequence repeats are considered to be cost effective and efficient molecular genetic markers for parentage analysis, linkage mapping, association studies, and genetic fingerprinting of cultivars. Currently, there is a small set of microsatellite markers available for Persea americana. We are expanding the number of available microsatellite molecular markers by screening pre-existing avocado expressed sequeance tag (EST)libraries. To date over 6183 sequences have been screened and 100 have been selected for marker development based upon the size, location, and type of microsatellite identified. The development of an additional 100 SSR markers, along with the currently available SSR markers, should provide suitable coverage of the avocado genome for assiciation studies and linkage mapping. These are the first steps in devising a marker assisted selection program for avocado.