The intralayer and interlayer excitation energy transfer between dioctadecylpyronine (PYR18) and dioctadecyl crystal violet (CV18) in alternating multilayer Langmuir-Blodgett (LB) films has been examined with picosecond time-resolved fluorescence decay measurements. The PYR18 fluorescence is efficiently quenched by energy transfer to CV18. The critical transfer distances of 65 and 67 Angstrom for intralayer and interlayer energy transfer, respectively, were calculated from spectral overlap. For the intralayer energy transfer system the fluorescence decay can be fitted with a two-dimensional Forster energy transfer equation, whereas for the interlayer energy transfer system it was necessary to allow the dimension to float in the Forster equation. By use of global analysis, a ''fractal dimension'' equal to 2.6 was obtained. With single-curve analysis the two-dimensional system is seen to approach the three-dimensional one with increasing CV18 concentration.