Devotees thronged the central Kolkata building since dawn to offer floral tributes and prayers at Mother Teresa's grave.
People from rural areas were seen kneeling before the grave with candles in hand as they sang hymns in memory of Mother Teresa, who died Sep 5, 1997.
Remembrance programmes were held at various schools.
Mother Teresa -- born Agnes Gonxha Bojaxhiu in Skopje, Macedonia, Aug 26, 1910, to an ethnic Albanian family -- made Kolkata her home and workplace for 68 years since 1929.
She was given the Nobel Peace Prize in 1979.