The Care Inspectorate - the independent body that scrutinises such services in Scotland - said there had been some improvement at the Pentland Hill Care Home in Edinburgh, but not enough.
A spokesman for the watchdog said its officers still had "significant concerns" although issues of staff training and rota management had been addressed and there was what was described as a genuine willingness now to bring the home up to acceptable standards.
The inspectorate had earlier found serious failings when it visited the home unannounced, and these were admitted by home operator Bupa.
The Care Inspectorate had given the home an initial deadline of last month to improve conditions but there will now be a review at the end of November at which point the home could close.
The improvements that have been set included a system to ensure medication was administered as prescribed, a requirement for staff to set up a different system of food, fluid and nutritional care, and the development of workers' training.
A Care Inspectorate spokesman said yesterday: "The block on new admissions remains. We require this care home to make further, specific improvements by the end of November, at which point we will reassess its licence to operate. The Improvement Notice remains in force.
"We are working closely with the council and NHS to safeguard residents.
Richard Jackson, director of operations for Bupa Care Homes said it would do what was necessary to reach the standards.
A source in the sector said that the Care Inspectorate will only close homes as a last resort as doing so can have a devastating impact on residents.