Single-chain particles of poly(ethylene oxide) (PEG) were prepared by spreading a 10(-4) wt.-% solution of PEO in benzene on a hot water surface. After isothermal crystallization at 317,2 +/- 0,1 K for 10 h, regular-shaped single-chain crystals were observed. A variety of typical morphologies were also found, and some of them are discussed on the basis of the habit of PEO crystals and various twin modes.