Technical Abstract: Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. S. Heidelberg has also been identified as an egg-transmitted pathogen. The deposition of Salmonella strains inside eggs is a consequence of reproductive tract colonization in infected laying hens, but prior research has not determined the relationship between the numbers of Salmonella that colonize reproductive organs and the associated frequency of egg contamination. In the present study, groups of laying hens in two trials were experimentally infected with large oral doses of strains of S. Enteritidis (phage type 13a), S. Heidelberg, or S. Hadar. Reproductive tissues of selected hens were cultured to detect and enumerate Salmonella at 5 days postinoculation and the interior contents of eggs laid between 6 and 25 days postinoculation were tested for contamination. Significantly more internally contaminated eggs were laid by hens infected with S. Enteritidis (3.58%) than with strains of either S. Heidelberg (0.47%) or S. Hadar (0%). However, no significant differences were observed between Salmonella strains in either the frequency or numbers of isolation from ovaries or oviducts. Salmonella isolation frequencies ranged from 20.8% to 41.7% for ovaries and from 8.3% to 33.3% for oviducts. Mean Salmonella colonization levels ranged from 0.10 to 0.51 log cfu/g for ovaries and from 0.25 to 0.46 log cfu/g for oviducts. Although parallel rank-orders were observed for Salmonella enumeration (in both ovaries and oviducts) and egg contamination frequency, a statistically significant relationship could not be established between these two parameters of infection.