Single-particle orbits are numerically followed in a time-dependent electric and magnetic field obtained from a two-dimensional magnetohydrodynamic simulation of bursty reconnection (Scholer and Roth, 1987). During the reconnection simulation the reconnection rate at the original X point decreases, a long current sheet develops, and reconnection sets in again at a new pair of X points. This leads to the development of a plasmoid. Particles injected with parameters appropriate for the plasma sheet at the time of the secondary tearing close to the new X points drift large distances parallel to the X line and gain high energies (up to ~300 keV). These particles are subsequently trapped on closed field lines in the developing plasmoid. Since the X line has a limited extent, the acceleration mechanism leads to large dawn-dusk asymmetries. The resulting distribution function within the plasmoid at various cross-tail distances is computed. The distribution function is close to an exponential in velocity with a higher-energy cutoff; with increasing distance toward the duskside the e-folding velocity increases, and the high-energy cutoff shifts to larger energies. ¿ American Geophysical Union 1987