Seeds of Orchis palustris Jacq. were primed for 1- to 5-day in polyethylene glycol (PEG-6000) solutions at -0.5, -1.0 or -1.5 MPa. The seeds were symbiotically germinated with BNR 8-3 mycorrhizal fungus on oatmeal agar at 22 °C. In general, priming hastened rapid germination. At -1.5 MPa water potential, the first to germinate was eight days compared to 18 days for the control. Percentage germination increased as priming water potential decreased, and the percentage germination was 55%, 58%, and 65%, at -0.5, -1.0, and -1.5 MPa, respectively, versus 43% for the nonprimed control. Priming duration from 1 to 5 days had little effect on germination performance. The best germination percentage (68%) was obtained from 1 day at -1.5 MPa treatment.