The Cubadebate website says Castro greeted a group of Venezuelans visiting the capital of Havana.
Cubadebate yesterday published four images that show Castro sitting inside a vehicle, each with a different person stretching an arm through the window to shake his hand.
Castro's face is largely obscured by a dark-colored baseball cap. He sports longish gray hair and a beard. The website said the encounter occurred Monday, but did not explain the delay in publishing the photos.
Castro will turn 89 on August 13. He was last seen in public at the inauguration of an artist's studio in January 2014.
Castro stepped aside temporarily as president due to serious illness in July 2006, and his brother Raul took over permanently in February 2008 after he was elected the country's new leader.