Forty-one patients with rheumatoid arthritis (RA) maintained on low dose prednisolone (mean 5.8 mg) participated in a double-blind cross-over study to determine the effect of timing (morning or night) of prednisolone dosage on morning stiffness. Prednisolone given at night resulted in a significantly shorter duration of morning stiffness (p = 0.0001) than did an equivalent dose given in the morning.