Rents in Gladstone have fallen in the past 12 months as new builds ease supply shortages.
The median weekly rent for two-bedroom townhouses dropped $120, according to PRDnationwide.
The rental price for three-bedroom units dropped by $70 per week.
Only single-bedroom units experienced a price rise, increasing $10 for a median weekly rent of $310.
PRDnationwide analyst Angus McLean warned investors may have to change their rental strategies.
"In order to secure a tenant on a good lease, investors in the Gladstone LGA have had to make adjustments to their rental price expectations," he said.
"But despite these rental price corrections over the past 12 months, high yields can still be achieved in the current market."
The drop in the rental market could be attributed to increased construction and a decrease in demand from retirees and sea-changers, according to PRDnationwide.
“Paired with recent falls in house and unit prices in the area, now could be the time to investigate a long-term strategy to residential investment in Gladstone,” Mr McLean said.