When Tigger first finds out about birthdays, he makes a bunch of wishes which cannot be fulfilled, resulting in an incredible adventure inside the Hundred Acre Wood's wishing well.
Pooh, Tigger, Piglet, Rabbit and Eeyore are at the wishing well. Piglet throws in a penny wishing for a penny. Rabbit is about to make a wish, but Tigger bounces on him, and his penny falls into the well. Pooh wishes for his birthday to come 7 to 8 times a year! Tigger wonders why his wishes never come true (despite the fact he uses buttons instead of pennies) and asks where he can find birthdays. Eventually, he discovers he doesn't have a birthday. Tigger's friends feel bad for him, and before you know it, they are throwing a first birthday party for him.
Tigger bounces into the woods to start his wishing, and Pooh, Piglet, Rabbit and Eeyore plan a meeting to see what they have got for Tigger. Piglet has got him an inflatable duck to help him swim, but it deflates when it hits a coat hook. Rabbit has got him a Tigger suit with a weight on the tail (to stop him bouncing). Pooh and Eeyore go to Tigger, who is still planning wishes (even wishing for the moon as a nightlight) and making a mud cake for ideas on what to get him, but cannot decide. Tigger's birthday party comes, and Eeyore gives Tigger himself, and Pooh gives him wrapping paper! At the time of the cake, Tigger wishes for everything.
But at the end, when Tigger learns there are no more presents, he is sad that he didn't get everything he wanted and walks out the house. Pooh leaves with an intent to catch the moon for Tigger, and sits on the roof of the wishing well with a fishing rod. When the moon's reflection appears in the wishing well, Pooh ends up falling into the well and entering Wishland, a secret place in the wishing well. Tigger, Rabbit, Eeyore and Piglet find out that Pooh has fallen in and try to rescue him, but end up falling in themselves. The place illuminates with giant balloons, birthday hats and ribbons everywhere.
They find a giant Tigger-striped cake with hundreds of candles. Tigger refuses to believe Wishland is real at first, but when his wishes of a PB&J sandwich and a root beer come true, he greedily starts wishing for random things, including stuff for his friends: for Pooh, a great big pot of endless honey; for Piglet, a gazillion bushels of acorns; and a thousand years' worth of carrots for Rabbit. However, the others aren't exactly happy, and Rabbit tells Tigger every time he makes a wish, a candle blows out, and now he's down to just two. Tigger then wishes for a banana split and a pogo stick, but Rabbit cuts him off on the second one. Now Tigger has only one wish left, and Rabbit insists that he use it to wish them home. At first, Tigger refuses, but then realizes that things would eventually get boring with no one to play with. Finally, Tigger uses his last wish to bring everyone home.
In the morning, Tigger wakes up in his home and finds some string leading out of his home. He follows it to the wishing well, and finds two presents for him. They are the two things he wanted most for his birthday: a banana split and a pogo stick! Soon, Tigger is wrecking Rabbit's garden with his pogo stick, much to Rabbit's chagrin.