The present invention provides a pharmaceutical composition, presented as a solid unit dosage form adapted for oral administration of sodium oxybate. The preferred unit dosage form is a tablet comprising a relatively high weight-percentage of sodium oxybate, in combination with a relatively small weight-percentage of total excipients. This permits the tablets to contain/deliver a pharmaceutically effective amount, e.g., about 0.5-1.5 g of sodium oxybate in each tablet with a delivery profile similar to that of the liquid form. The tablets are bioequivalent to the liquid form.