The photos of Felipe, Prince of Asturias and his two daughters Leonor and Sofia were taken in August 2012 to mark the 40th birthday of their mother, Princess Letizia, but published on Monday on the official palace Twitter account.
They show the future King Felipe VI smiling and relaxed, demonstrating the close relationship he is said to have with his children.
Palace publicists will hope that the uncontroversial images of the royal family can boost enthusiasm for the institution at a time when it is under great scrutiny.
Although Felipe and 'commoner' Letizia, whom he married in 2004, have been untainted by scandal, many of his closest family members have hit the headlines in recent years for the wrong reasons.
The future king's sister, Cristina, was officially named a tax crime suspect in relation to her husband's allegedly improper business practices earlier this year.
And rumours continue to swirl around the reasons why the outgoing King Juan Carlos might want or need lifelong legal immunity after his abdication.
Public support for a referendum on the future of the monarchy was recently reported to be as high as 62 per cent.