The incident took place at Boxanagar of Sonamura sub-division Sipahijala district on Thursday night.
It has been raining heavily in and around Boxnagar since Thursday evening.
Along with rains, lightning incidents have also been reported from various parts of Tripura.
All the injured are from Rahimpur village in Boxnagar.
The injured have been identified as Ruzina Akhter, Jaitan Bibi, both of them are middle-aged and 15-year-old Mahinur Akhter.
All the three injured are residents of the same area.
They received burn injuries due to lightning strike in various parts of their bodies.
They fainted immediately after the incident and were immediately taken to Boxnagar Primary Hospital on Thursday night.
While one was released after initial treatment, the two others are undergoing treatment at the hospital.
Boxanagar is around 50 km from the capital, Agartala and is located near the Indo-Bangla border.