In a retrospective survey of 46 conservatively treated patients with obstetric brachial plexus palsy (OBPP) the following conclusions were reached. An immediate examination of the neurological status of the neonate root by root is essential for proper analysis of the course of the recovery. Mild cases with C5-C6 root injury (Erb's palsy) have a good outcome and may be treated conservatively. Intermediate cases with C5-C7 root injury with additional drop hand require close observation as early as age 3 weeks when the first electromyographic (EMG) examination is indicated. The second EMG should be performed at age 11-12 weeks. If the function of the brachial biceps muscle is lacking at age approximately 12 weeks (3 months), microsurgical intervention should be considered; such intervention definitely is required at age 5 months if the paresis in the brachial biceps muscle has not recovered. Severe cases with C5-C8 or C5-Th1 root injuries with flaccid abducted arm, wrist drop, claw hand, and possibly head tilt to the contralateral side and Horner's sign should be operated on primarily at age 1-2 months.