Priyanka uploaded a picture from their childhood and called him the "best brother in the world", and said that things haven't changed much since childhood.
"Rahul Gandhi I guess things haven't changed that much, haan?! ..best brother in the world!," she said in a tweet.
This is not the first time that the Gandhi siblings have expressed their affection for each other.
In April this year, while campaigning for the Lok Sabha polls, Priyanka Gandhi and Rahul Gandhi had met each other at the Kanpur airport and shared a few light-hearted moments.
Posting a video of their meeting on Facebook, Rahul Gandhi had written: "Was nice meeting Priyanka at Kanpur Airport! We're headed to different meetings in UP."
"Let me tell you what it means to be a good brother. What it means is that I am doing these massive long flights and I am going in a little helicopter squeezed up. And she is doing short flights and going in a big helicopter," Rahul Gandhi had added.
In the video, Rahul wrote: "Love you sis." Priyanka Gandhi could be seen laughing and saying "that is not true".