Only one key public event has been scheduled each day. The pontiff is scheduled to travel from the capital as far as Roznava 400km to the east.
Privately, some Vatican aides said on Thursday the visit may well be his last foreign trip for some time, if not for good.
There were new health fears for Pope John Paul after he was unable to finish a speech marking his arrival in Slovakia.
The pope could only read the first few sentences of his speech at Bratislava airport. Aides called on a Slovak priest to continue the reading.
After several minutes of rest, the Pope then picked up the reading again.
The pope suffers from Parkinson's disease and crippling hip and knee ailments, has appeared short of breath and his voice has been weak during recent public appearances.
But in a welcoming address, Slovakian President Rudolf Schuster hailed him as a "high moral authority" who was bringing "a message of hope."
More than 1000 people flocked to the airport fence to welcome him, waving Slovakian and yellow-and-white Vatican flags, as he was greeted by Slovakia's top state officials and Catholic leaders.
It is his third visit to the former communist central European country and the 102nd foreign trip of his globetrotting quarter-century pontificate.