Venusaur appeared in the episode Cutting the Ties that Bind, where it was first seen near a campfire next to Spenser, who was making medicine for Pikachu who was lost at the time.
The next day, Spenser and Venusaur accompany May, Max, Brock, and Scott on their search for Ash. They find him and Sceptile being attacked by many Beedrill, and Venusaur helped them by using Sweet Scent to calm them down.
In the next episode, Ka Boom with a View!, Venusaur was used as the second Pokémon in the battle after Shiftry. Ash used Heracross for the battle. It was able to put up a good fight, but was eventually defeated by Venusaur's powerful Solar Beam. Ash then sent out Swellow, who utilized its speed and agility to its full advantage. It was able to defeat Venusaur after a hard fought battle.
It made another appearance in a flashback in King and Queen for a Day!.