While smoking might be viewed as the least of their problems, people experiencing homelessness, mental illness and alcohol and other drug dependence are crying out for the right support to quit, according to the Public Health Association of Australia.

A new study, published in the Australian and New Zealand Journal of Public Health this month, showed a majority of the people surveyed were interested in quitting smoking but often had a lower success rate due to their unique challenges.

Researchers surveyed 84 smokers struggling with a mix of homelessness, mental illness and substance dependence in Western Australia, with the majority saying doctors were the best people to help them quit.

However, a minority of doctors were less likely to recommend respondents quit smoking if they thought it would be too much of a burden.

"I'm trying to quit meth and I'm trying to quit marijuana and I miss my kids and all that sort of stuff. And to quit smoking at the same time, I got told by my GP not to do it," one male respondent said.

PHAA CEO Terry Slevin, who co-authored the study, says smoking cessation needs to be a higher priority among some GPs and generally among community service organisations.

"The truth is that while smoking might be seen as a smaller issue that these individuals are facing, it actually feeds into their overall poor health and then continues an ongoing cycle of disadvantage," he said.

Study co-author Professor Simone Pettigrew says the research shows where policymakers and governments can effectively direct "smoking cessation dollars" in a community where the habit is entrenched.

"This is a worthwhile area ... rather than considering these groups as too hard, we want to show this is actually a good opportunity."

Prof Pettigrew said she was surprised by the strong desire to quit among those surveyed, and their previous attempts to do so.

"They don't need to be convinced, they just need to be helped," she told AAP.

While community service organisations could do more to upskill staff, and providing cessation support for staff themselves, they need the right resourcing and funding because they are already operating on a "shoestring budget," Prof Pettigrew said.

In addition, general practitioners should receive information that gives them confidence smoking cessation can be prescribed while treating other conditions simultaneously.

Quitline was identified as a known source of help, but many of those surveyed said they needed greater emotional support from someone they trust, such as a GP or health worker.

Respondents also showed less awareness of online resources and didn't perceive them to be useful, the study showed.

The research was conducted by Curtin University and the Cancer Council, and funded by a Western Australia government initiative called Healthway.

Australian Associated Press