More than half of those questioned said they believe marijuana has medical benefits, while a larger majority agreed the drug is addictive.
AARP, with 35 million members, says it has no political position on medical marijuana and that its local branches have not chosen sides in the scores of state ballot initiatives on the issue in recent elections.
But with medical marijuana at the center of a Supreme Court case to be decided next year, and nearly a dozen states with medical marijuana laws on their books, AARP decided to study the issue.
"The use of medical marijuana applies to many older Americans who may benefit from cannabis," said Ed Dwyer, an editor at AARP The Magazine, which will discuss medical marijuana in its March/April issue appearing in late January.
Among the 1,706 adults polled in AARP's random telephone survey in November, opinions varied along regional and generational lines and among the 30 percent of respondents who said they have smoked pot. AARP members represented 37 percent of respondents.
Overall, 72 percent of respondents agreed "adults should be allowed to legally use marijuana for medical purposes if a physician recommends it." Those in the Northeast (79 percent) and West (82 percent) were more receptive to the idea than in the Midwest (67 percent) and Southwest (65 percent). In Southern states, 70 percent agreed with the statement.
Though 69 percent of those age 70 and older said they support legal medical marijuana use, less than half agreed it has medical benefits. Seventy percent of respondents age 45-49 said they believe in the medical benefits of pot, as did 59 percent of those in the 50-69 age group.
And while 74 percent of all people surveyed said pot is addictive, older respondents were more likely to think so: 83 percent of those 70 and older, compared with 61 percent of those aged 45-49.
Generational lines also divided those who have smoked pot: Just 8 percent of those 70 and older admitted having lit up, compared with 58 percent of the 45-49 group, 37 percent of those between 50 and 59 and 15 percent of the 60-69 set.
National polls in recent years have found majority support for allowing the use of marijuana for medical purposes.
Last month, the Supreme Court heard arguments over whether federal agents can pursue sick people who use homegrown marijuana with their doctors' permission and their states' approval.
The Bush administration has argued that allowing medical marijuana in California would undermine federal drug control programs, and that pot grown for medical use could end up on the illegal market and cross state lines.
The AARP poll of adults age 45 and older was conducted Nov. 10-21 by International Communications Research of Media, Pa. The margin of sampling error was plus or minus 2.5 percentage points.