It is currently forecast that the total spent on agency staff by the end of this financial year will be £4.1 million.
The total spend so far is £2,070,378.
Among the agency staff used by Shropshire Council, there have been 69 social workers, 19 assessors, four team managers and two service managers.
The average length of placements is 34 weeks, and the longest active placement is currently 111 weeks.
Councillor Pam Moseley requested the information ahead of Shropshire Council's meeting on Thursday.
Councillor Steve Charmley, Portfolio Holder for Corporate Support, said in his reply to Councillor Moseley that some of the teams are facing areas of "recruitment shortages" where it is "difficult to attract permanent staff".
He said: "Agency staff have an important role in providing flexible and knowledgeable staff to teams who need extra support.
"When teams are undergoing service redesign or peaks in workflow or staff absence, temporary agency staff gives managers another resource to help deliver the necessary service function.
"Some of our teams are also facing areas of recruitment shortages, where it is difficult to attract permanent staff.
"With the introduction of the Agency Worker Regulations in October 2011, temporary workers have the same employment terms and conditions as our permanent employees after 12 weeks of continuous employment in the same role.
"We currently use Matrix SCM as our managed service provider, which is a portal for managers to advertise to a wide supply chain and manage the appointment and timesheets in an efficient manner. "Not all placements are on Matrix, so the management information we have on these placements is not as detailed."