May first met a Beautifly belonging to Janet, a Coordinator who inspired May to participate in Pokémon Contests. Wanting to have a Beautifly of her own, she uses her Torchic to battle against a wild Wurmple and catches her first Pokémon. Jessie also catches a Wurmple at the time.
In the episode A Corphish Out of Water, May's Wurmple evolved into a Silcoon while battling against Jessie's Wurmple after it evolved into a Cascoon. Soon after, May's Silcoon evolved into a Beautifly while battling Jessie's Cascoon. Later, Jessie's Cascoon evolves into a Dustox.
Since then, May has used Beautifly in multiple contests as well as a PokéRinger competition, where she lost to Jessie's Dustox while being used by James. She was used in the Hoenn Grand Festival, in the Appeal Round, scoring pretty highly with just a single Silver Wind. After losing in the Grand Festival to Drew, she heads home, leaves Beautifly and her Skitty there, and heads to Kanto.
After losing in the Grand Festival to Solidad, and became depressed about her loss, she temporarily recalls Beautifly to her party in the The Unbeatable Lightness of Seeing!, where she used in a battle against Drew. Teamed up with May's Combusken, Beautifly battles against Drew's Roselia and Butterfree. Despite both her Pokémon having a type advantage, as well as Beautifly's recently learned Psychic, May loses the battle, but regains her confidence.
|String Shot||All in a Day's Wurmple|
|Tackle||Seeing is Believing!|
|Gust||Seeing is Believing!|
|Silver Wind +||Now That's Flower Power!|
|Morning Sun +||Cruising for a Losin'|
|Psychic (move) +||The Unbeatable Lightness of Seeing!|
|Aerial Ace +||Strategy with a Smile!|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
May's Beautifly resembles Dawn's Buneary, as both were the first Pokémon they caught and were the first Pokémon they used in a contest.