Yes. Most moms can produce at least some quantity of breast milk for their adopted babies. And, even if you aren't able to produce enough milk for exclusive breastfeeding (some moms can, some can't), there are lots of benefits to breastfeeding anyway. For one, breastfeeding fosters an increased sense of security and an invaluable bond between mother and babe. Plus, any amount of milk you are able to produce will supply baby with antibodies and other super-nutritious stuff to give him the best start in life.
To increase your odds of milk production, work with an experienced, certified lactation consultant who can offer hands-on support as you work to stimulate milk production and teach (or re-teach) your baby to breastfeed. Your regimen to produce milk might include hormone therapy to simulate pregnancy, pumping or hand-expressing milk, frequently nursing (at least every two to three hours) once baby arrives, and maybe even some herbal or prescription supplements (galactagogues) that can help build your supply. Once baby is in your arms, you can give him any necessary supplements (formula or breast milk) with a nursing supplementer, so that he can learn to nurse while he fills his tummy.
Experts urge adoptive breastfeeding moms to focus more on the breastfeeding relationship than the actual milk. Bonus: Moms who are more relaxed and focused on baby often produce more milk.