Tuberculosis has increased four-fold in some areas of London over the last 10 years, according to a new report.
Tuberculosis can affect the lungs and bones.
The London Assembly's Health Committee said the disease was making a "worrying comeback" in London but levelling out in the rest of the UK.
Almost half of the 6,891 new cases of TB in England and Wales were in London by 2002 compared to only three in 20 in the 1980s.
The report calls for health checks and a raising of awareness of the disease.
TB was a major cause of death in the UK until about 50 years ago when new drugs became available to treat it.
The London boroughs of Hillingdon, Enfield and Greenwich all saw a four-fold increase in the disease, the report said.
In Barking, Ealing, Hackney, Islington and Lewisham the number of cases have doubled since the early 1990s.
The committee also found that strains of TB which were resistant to drugs were more common in London than elsewhere and those cases were also more expensive to treat.
It said carrying out health checks in local communities would be more effective than screening people when they arrive in the UK.
Committee chairwoman Elizabeth Howlett said: "After a century in decline, TB is making a worrying comeback in the capital with increasing numbers of Londoners contracting the disease.
"We have not yet reached a crisis point in London and we must make sure that we do not.
"Failure to heed the rising rates in London and to ensure adequate TB control now could result in major problems and expenditure in the future, particularly with the emergence of multi-drug resistant strains."