Del. Dana Dembrow, D-Montgomery, said marijuana is currently legal for medical purposes in eight states, so "we're not plowing new ground here."
The sponsor of the bill, Del. Donald Murphy, R-Baltimore County, said no medical marijuana users have been prosecuted by federal authorities in those eight states to date.
"Some people don't have time to wait for Washington to quit (messing) around," said Del. David Brinkley, R-Frederick, who went through radiation therapy for lymphoma in 1989.
Del. B. Daniel Riley, R-Harford, broke down as he told the story of an elderly friend who was painfully dying of cancer but refused to try marijuana because it's illegal.
His treatments became so painful that he contemplated suicide before he quit them, Riley said.
"We buried Larry two months ago. If we as a legislative body could have been more compassionate in our decisions maybe Larry would still be here today," Riley said.
While none of the lawmakers said they smoked pot during their cancer treatments, other cancer survivors testified that it gave them the only relief from their pain and nausea.
"I believe it enabled me to live. Please don't let us die and waste away," said Larry Silberman of Rockville, Md., who said he used marijuana while suffering from non-Hodgkin's lymphoma.
Silberman said the marijuana helped stimulate his appetite while he was enduring extreme nausea and pain.
Support has been building in the legislature to legalize marijuana for medical use since Murphy first proposed the idea two years ago.
Similar legislation died in a Senate committee last year and was killed by the House Judiciary Committee the previous year.
This year the bill has 53 co-sponsors in the 141-member House, including Del. Sue Hecht, D-Frederick/Washington, and Del. Louise Snodgrass, R-Frederick/Washington.
A doctor and a nurse in the legislature testified in favor of the bill.
The proposal would allow people with diseases such as cancer or AIDS to use marijuana on the recommendation of their physicians. The Department of Health and Mental Hygiene would issue registry identification cards for patients eligible to take the drug.
Patients or primary caregivers could grow up to seven marijuana plants indoors for medical use and possess up to three ounces of useable marijuana. Doctors could recommend use for medical conditions that include cancer, glaucoma, AIDS, severe pain and nausea, epilepsy and multiple sclerosis.
The bill is named after Darrell Putman, a former Army Green Beret from Howard County who turned to marijuana for medicinal purposes to treat his cancer before he died in 1999.
Opponents of the bill include the Drug Enforcement Agency, the doctors' lobby, Maryland State Police and Drug-Free Kids. No one from those groups testified at Wednesday's bill hearing.
"I kind of feel like a sacrificial lamb here," said Doug Stiegler, executive director of the Family Protection Lobby, the only opponent to speak.
Stiegler said the state should have compassion in cases in which people use marijuana for medical purposes.
"I do commend Delegate Murphy and others for their compassion. Unfortunately, I think this law goes too far beyond that," he said.
Stiegler said he doesn't think the state should let people grow pot in their homes, even for medical use. And sanctioning it for medical purposes will encourage marijuana advocates to push for full legalization, he said.
Stiegler suggested lawmakers pass one of the alternatives they have before them. One bill would let people use medical use as a defense if they're arrested. Another would let judges take it into consideration at sentencing.
Under current law, marijuana possession is a misdemeanor subject to a $1,000 fine or one year in prison.
The Associated Press contributed to this story.