This study was carried out in order to determine the species diversity, abundance, and distribution and seasonal frequency occurrence times of the eggs and larvae of Teleost fish in Izmir Bay during 1989-1990. A total of 32140 eggs and 6582 larvae were collected from plankton samples and 69 species belonging to 27 families were identified. The most abundant families included Spariclae 23.79%, Clupeiclae 24.63%, Mullidae 12.22%, Serranidae 8.72% and Mugilidae 8.04% of total eggs, and Gobiidae 67.38%, Sparidae 9.43% and Blennidae 9.31% of total larvae. In this study, with regard to eggs, because some species preferred to release their eggs in clean water, stations in the outer bay showed similarities, while stations in the middle bay formed various groups amongst themselves. From the point of view of larvae, apart from station 2, which was near the lagoon area in the middle bay, the other stations were similar. The reason for this is the abundance of species of the Gobiidae family specific to that area. In areas with a low diversity index in respect of eggs, the presence of dominant species was detected. The highest diversity index and frequency of occurrence of fish eggs and larvae were determined in spring, the reason for this being that the spawning period of many fish species in Izmir Bay begins at the end of spring. In the middle and outer bay, where the stations in this study were situated, the pollution in Izmir Bay was found generally not to influence the species diversity of fish eggs and larvae.