Burial space in Cardiff is reaching a near-critical level, according to a council report.
Cardiff does not re-use old graves like some other authorities
If something is not done, two of the city's largest cemeteries could be full within five years, it said.
The 50-year-old crematorium at Thornhill is also in a poor condition and in need of modernisation.
Proposals including upgrading the crematorium and developing new burial areas will go before the council's executive later this week.
The report into council bereavement services is the result of a study by the Community and Adult Services Scrutiny Committee.
The committee concluded that the current situation created a negative impression of Cardiff and the council to the thousands of people attending funerals each year.
It also made the continued delivery of high-quality funeral services difficult for both the staff and the other professionals involved, it said.
It has been estimated that Thornhill cemetery could be full within three to four years, followed by Western cemetery in Ely in five years.
The report, which goes to the council on Thursday, contains recommendations including:
Implementing the full programme of improvements for Thornhill crematorium
Development of new areas for burial and the range of burial options
Raising the profile of the service internally by ensuring bereavement services are considered fully in any new policies
Developing new areas for burial at the two main cemeteries and creating a new cemetery.
Committee chair councillor Brian Finn, Labour, said: "Providing quality services for the bereaved is critically important but often doesn't get the profile it deserves.
The council is being urged to take action
"In an era of huge demands on resources and land, bereavement must not be allowed to slip down our list of priorities. "
Cardiff council deals with over 4,000 funerals each year and more than 700,000 people visit its cemeteries and crematorium. More than 2,500 cremations take place each year.
The city is ranked 22 out of 82 in the Institute of Cemetery and Crematorium Management's league table of authorities providing burial and cremation services.
The report says burial space capacity has "reached a near-critical point" - a situation made worse by the increase in the population of Cardiff by 95,000 since the last cemetery - at Thornhill - was opened in 1953.
It points out that, although the council's Unitary Development Plan (UDP) makes reference to the need for additional cemetery space, it makes no commitment to build one.
At present, Cardiff Council does not allow the re-use of old graves, though other authorities have had to do so to cope with demands.
Conservative councillor Jon Burns said: "It is very clear the current situation is unsustainable as the report has highlighted.
"The council will need to think long and hard about viable alternatives for burial sites."
Plaid councillor Delme Bowen said: "The upgrading at Thornhill is long overdue both in respect of the improvement of quality and capacity."
The Liberal Democrats were not immediately available for comment.