Health Ministry officials said Sunday the three patients in western Gujarat state had recovered.
"There is no need to panic," Dr Soumya Swaminathan, a top health ministry official, told reporters.
The World Health Organisation said in a statement released that the three cases that India reported to the WHO on May 15 were detected through routine blood surveillance in a hospital in Ahmadabad, Gujarat's capital. Two cases were detected in February and November last year, while a third case was detected in January this year.
Swaminathan, who heads the Indian Council of Medical Research, said the three patients had not travelled overseas and had acquired the infection locally.
The virus is spread by the daytime-active Aedes mosquito.
The WHO says although Zika symptoms are mild and no deaths have been reported globally, it sometimes causes complications including microcephaly and Guillain-Barre syndrome.
Babies born to Zika-infected mothers have been found to have microcephaly, or a birth defect where the head is abnormally small and brains might not have developed properly. Guillain-Barre syndrome is a disorder in which the body's immune system attacks part of the peripheral nervous system.
