Sushma Swaraj, India's former Indian minister of external affairs, called it a "great victory for India".
"I thank the Prime Minister Shri Narendra Modi for our initiative to take Jadhav's case before International Court of Justice. I thank Mr. Harish Salve for presenting India's case before ICJ very effectively and successfully. I hope the verdict will provide the much needed solace to the family members of Kulbhushan Jadhav," she said in a series of tweets.
Kulbhushan Jadhav, a former Indian navy officer, was arrested in Pakistan's southwestern province of Balochistan in March 2016 on charges of espionage.
The 48-year-old was then sentenced to death by a Pakistani military court in 2017, sparking outrage in India.
India insists that Jadhav was not a spy and says he was kidnapped in Pakistan.
New Delhi has been asking the ICJ to order Islamabad to annul the sentence.
India's lawyers told the court in February that it was a "farcical case" based on "malicious propaganda", while Pakistan's lawyers hit back by accusing Jadhav of "terrorism"