NHS Tayside employs more than 1,300 people on controversial zero-hours contracts.
Zero-hours contracts are growing in popularity across the UK but have been heavily criticised because they give employees no guaranteed earnings.
They are used for staff who are kept on standby and only required to work when needed.
It is estimated there are now one million people in the UK on zero-hours contracts.
Although they are useful for those who need flexible hours, the union Unison claim they are unfair on the vast majority of workers who have no idea what sort of wages they will earn one week to the next.
Although NHS Fife has not employed anyone on zero-hours contracts in the past three years, they are becoming increasingly popular at NHS Tayside.
There were 1,326 people on these contracts in March 2013, compared to 1,186 two years earlier. These include 229 medical and dental staff, as well as 106 other health care workers.
There are also 711 nursing and midwifery staff on zero-hours contracts, up from 556 in 2011.
Additionally, 120 support services staff and 102 administrative services staff are also on such contracts.
A spokesman for NHS Tayside said: “The rise in the number of nurses who meet the above definition is due to the fact that we have an increased number of nurses registered with NHS Tayside nurse bank.
“NHS Tayside’s nurse bank register enables us to have a pool of nurses who wish to work flexibly and are able to provide cover for unexpected staff absences and unanticipated increases in clinical activity and patient acuity.”
Royal College of Nursing (RCN) professional officer Ros Shaw said: “Zero-hours contracts offer no formal protection for staff and no benefits such as sick pay or holidays.
“It’s a working practice that creates a lot of stress for employees, and the RCN would not recommend it. However, many nurses work zero-hours contracts when they join a nurse bank.
“For the majority of these nurses it’s a way to supplement their income from their existing contract with the health board, or work flexibly to help cope with managing child or other caring responsibilities.
“Student nurses also join a nurse bank to earn more money to support themselves while at university.
“So we’re not opposed to bank nursing in such circumstances. But we are clear that bank nurses should never be a replacement for NHS permanent contracted nurses and only used in the short term, for example, to cover holidays and other absences.”
However, Dave Watson from Unison said while they accepted zero-hours contracts may work for nursing bank staff, they should not be used for other employees.
“Our general position is that we are opposed to the use of zero-hours contracts,” he said.
“The problem for people who are on them is they cannot get mortgages, there is no guaranteed incomes and it creates a level of uncertainty that is very bad for the local economy.”