A knowledge of the size-velocity distribution of ejecta from impact craters is important for a number of processes that occur or may have occurred in the solar system, such as planetary accretion, collisional evolution ofasteroids, the ejection of meteorites from parent bodies larger than asteroids (such as the lunar meteorites and the SNC meteorites, which may be from Mars), and massive biological extinctions on the Earth. In order to estimate the size-velocity distribution of impact crater ejecta, the sizes and ranges from the primary crater were measured for the secondary craters of twelve large craters on Mercury, the Moon and Mars. The ballistic equation for spherical bodies was used to convert the ranges to velocities, and the velocities and crater sizes were used in the appropriate Schmidt-Holsapple scaling relation to estimate ejecta sizes. Assuming that ∝v-B, lines were fitted to the log (maximum size) vs. log (ejection velocity) using the least squares method to determine the velocity exponent. Certain problems with data collection, such as partial burial of some craters and interference from other craters and topographic features, made it impossible to determine a simple, unique relation between size and velocity. The velocity exponents are generally between -1 and -3, with an average value of approximately -1.9. The complicating effect of secondaries produced by clusters of impactors implies that the calculated lines are probably steeper than the slopes of the ''true'' fragment size-velocity distributions. ¿American Geophysical Union 1987