63-year-old Modi reached the country's premier medical institute at 7 AM and spent around six hours during which he underwent tests that included an ECG and Echocardiogram, sources said.
The AIIMS hospital was turned into a fortress till Modi left the place.
There was a huge security presence in the hospital premises with police personnel keeping a close vigil in front of the building and at the Metro station. Several shops also remained closed.
Sources said Modi's visit to AIIMS was a routine medical check-up that he undergoes every three months.
Modi's visit did not affect the normal functioning of the AIIMS, a senior doctor said.