The accident occurred on Mumbai national highway near Madinaguda in Miyapur on the outskirts of Hyderabad when the driver apparently lost control of the vehicle.
The heavy truck ran over a road-side nursery, killing three persons including two from the same family.
While Srinivas and Adibabu of West Godavari district of Andhra Pradesh were killed on the spot, Krishnamurthy succumbed to his injuries at Gandhi Hospital.
Police suspect that the driver dozed off, leading to the accident. The truck was on its way from Kukatpally to BHEL on the national highway.