In addition to brainstem sites of action, analgesia can be elicited following amygdala microinjections of morphine and μ-selective opioid agonists. The present study examined whether opioid analgesia elicited by either morphine or β-endorphin in the amygdala could be altered by either the general opioid antagonist, naltrexone, the μ-selective antagonist, β-funaltrexamine (BFNA) or the δ 2 antagonist, naltrindole isothiocyanate (Ntii) in the periaqueductal gray (PAG). Both morphine (2.5–5 μg) and β-endorphin (2.5–5 jig) microinjected into either the baso-lateral or central nuclei of the amygdala significantly increased tail-flick latencies and jump thresholds in rats. The increases were far more pronounced on the jump test than on the tail-flick test. Placements dorsal and medial to the amygdala were ineffective. Naltrexone (1–5 μg) in the PAG significantly reduced both morphine (tail-flick: 70–75%; jump: 60–81%) and β-endorphin (tail-flick: 100%; jump: 93%) analgesia elicited from the amygdala, indicating that an opioid synapse in the PAG was integral for the full expression of analgesia elicited from the amygdala by both agonists. Both BFNA (68%) and Ntii (100%) in the PAG significantly reduced morphine, but not β-endorphin analgesia in the amygdala on the tail-flick test. Ntii in the PAG was more effective in reducing morphine (60%) and β-endorphin (79%) analgesia in the amygdala on the jump test than BFNA (15–24%). Opioid agonist-induced analgesia in the amygdala was unaffected by opioid antagonists administered into control misplacements in the lateral mesencephalon, and the small hyperalgesia elicited by opioid antagonists in the PAG could not account for the reductions in opioid agonist effects in the amygdala. These data indicate that PAG δ 2 and to a lesser degree, μ opioid receptors are necessary for the full expression of morphine and β-endorphin analgesia elicited from the amygdala.