Nurses have been told not to flirt with patients by the Australian Health Practitioner Regulation Agency (AHRA).
Sexual innuendo, "off-colour" jokes and offensive language, are also out in the new guidelines. Those who breach the code will be disciplined, the AHRA has said.
The rules which came into effect from July 1 and October 18 in Western Australia state it is the nurse's responsibility to ensure they maintain a "professional boundary" even if a patient initiates or consents to sexual conduct.
Nurses must also keep an eye out for any patients developing a crush, as failing to recognise attraction of a sexual nature is also considered sexual misconduct or assault.
Nurses have been warned that discussing personal problems, feelings of sexual attraction or aspects of their personal life with patients could be interpreted as sexual violations.
The rules state sexual misconduct is an "extremely serious violation of the nurse's professional responsibility to the person in their care", and could result in dismissal.
According to the most recent figures published by the NSW Nurses and Midwives Board, there were 17 complaints made about nurses with "professional boundary issues" in the year to June, 2009 - almost triple the number in the previous year, when there were only six.
A total of 47 complaints relating to the issue have been made in the past five years.
Agency spokeswoman Nicole Newton said complaints about professional-boundaries issues were typically among the top 10 complaints reported about nurses.
The guidelines also stipulate that nurses must not accept bus fares, meal tickets, money or goods from patients.
NSW Nurses' Association general secretary Brett Holmes said it was the first time there had been specific guidelines on flirting. He was concerned nurses could be punished for being friendly to patients.
"It's a fairly high bar as flirting becomes crossing a professional boundary. Is [flirting] being fairly jocular or having a light-hearted conversation in what can be a very difficult situation, when it's therapeutic to lighten the load?" he said.
Mr Holmes said the medical tribunal should take "a balanced view rather than trying to make a black-letter law on what is or isn't flirting".
Liquor, Hospitality and Miscellaneous Union assistant secretary Carolyn Smith said the guidelines were condescending. She compared them with classroom rules set up for scolded schoolchildren.
"Nurses play such a critical role in patient care. We should be supporting them, not putting a whole raft of silly guidelines in front of them," Ms Smith said.
Curtin University head of nursing and midwifery Phillip Della said nurses were often considered to be the most trustworthy professionals in the community.
Prof Della, who was formerly the chief of nursing in WA, said this meant staff had enormous expectations to meet.
"One of the problems is that because nurses have to deal so intimately with patients, it can quite easily slip over into unethical behaviour," he said.
"These new guidelines spell out very clearly how a nurse can get into trouble so there is no confusion. For example, for a young nurse working in an orthopedic ward it helps if it is clear what is unacceptable."