Germination and seedling length of soybean seeds (cultivar: Williams) with and without polyethylene glycol-8000 (PEG) treatments were measured following preconditioning at two temperatures (15 and 30$^{circ}C$) and two moisture levels 〔low (30 percent) and high (50 percent seed water content)〕 for 0, 2, 4, or 8 days. A split-split plot in time was used with four replications. Observations were made after two days of germination at 30$^{circ}C$ Seedling growth accelerated with two days of preconditioning at 30$^{circ}C$, but was reduced as preconditioning duration increased up to eight days at the same temperature. PEG treated preconditioned seeds exhibited reduced moisture uptake and seedling growth. Preconditioning at a high moisture level increased seedling moisture content and also increased seedling length until four days of preconditioning duration. Seedling dry weight decreased when preconditioning temperature was 30$^{circ}C$ and when the high moisture level of preconditioning was continued for eight days.