"Paying tributes to the proud son of India, the inspiring Lal Bahadur Shastri ji," Modi tweeted after paying tribute to the second Prime Minister of India.
Modi paid tribute to him at a bust erected in Shastri's memory.
A prominent figure in the independence movement, Shastri died of a heart attack in Tashkent in 1966 during an official visit at the age of 61.
Shastri had taken over the office of Prime Minister after Prime Minister Jawaharlal Nehru's death in 1964.
"We are thankful to the people of Tashkent and Uzbekistan, for preserving the legacy of our former Prime Minister," Modi had said yesterday.
Modi, who arrived here yesterday on the first leg of his eight-day visit to Central Asia and Russia, also paid tribute at the National Monument of Independence and Humanism.