A solid, controlled release, oral dosage form, the dosage form comprising an analgesically effective amount of an opioid analgesic or a salt thereof, coated with a controlled-release coating or in a controlled-release matrix, wherein the dissolution rate in-vitro of the dosage form, when measured by the USP Paddle Method at 100 rpm at 900 ml aqueous buffer (pH between 1.6 and 7.2) at 37° C is from about 12.5% to about 42.5% (by wt) opioid released after 1 hour, from about 25% to about 65% (by wt) opioid released after 2 hours, from about 45% to about 85% (by wt) opioid released after 4 hours and greater than 60% (by wt) opioid released after 8 hours, the in-vitro release rate being substantially independent of pH and chosen such that the peak plasma level of said opioid obtained in-vivo occurs from about 2 to about 6 hours after administration of the dosage form.