1 :01x01 - Ben 10 Returns (1)

When Grandpa Max is discovered to be missing, Ben sets out with Gwen and Kevin 11 to find him. While on their search they uncover a secret weapons trade which is being held between two alien groups.

2 :01x02 - Ben 10 Returns (2)

Ben, Gwen, and Kevin stow away aboard the ship of their new alien adversaries, and discover that their leader is plotting a campaign to exterminate the human vermin of Earth. Ben also discovers that the Omitrix no longer protects his human form from damage whenever his alien forms are harmed

3 :01x03 - Everybody Talks About the Weather

The gang runs into a Heatblast as they search for other Plumbers who are using Grandpa Max's badge.

4 :01x04 - Kevin's Big Score

5 :01x05 - All that Glitters

6 :01x06 - Max Out

7 :01x07 - Pier Pressure

8 :01x08 - What Are Little Girls Made Of?

9 :01x09 - The Gauntlet

Ben steals a robotic glove from Kevin's GTO to battle the bullies, but it causes trouble instead.

10 :01x10 - Paradox

A time traveling hero joins forces with the gang to battle a monster ripped straight from the 1950s.

11 :01x11 - Be-Knighted

Ben is torn between his mission and the escaped dragon he has captured from the Forever City after learning about both sides of the conflict.

12 :01x12 - Plumbers' Helpers

13 :01x13 - X Equals Ben Plus 2 (X = Ben + 2)

14 :02x01 - Darkstar Rising

15 :02x02 - Alone Together

16 :02x03 - Good Copy, Bad Copy

17 :02x04 - Save the Last Dance

Ben is afraid he has lost control of Omnitrix.

18 :02x05 - Undercover

The DNAliens have kidnapped a child genius so he can build them a mystery arch.

19 :02x06 - Pet Project

20 :02x07 - Grounded

21 :02x08 - Voided

22 :02x09 - Inside Man

23 :02x10 - Birds of a Feather

24 :02x11 - Unearthed

25 :02x12 - War of the Worlds (1)

26 :02x13 - War of the Worlds (2)

27 :03x01 - The Vengeance of Vilgax (1)

Vilgax, whose power has been greatly increased, challenges Ben for a battle with the winner named ruler of earth.

28 :03x02 - The Vengeance of Vilgax (2)

After tampering with the Omnitrix, Ben, Gwen and the now mutated Kevin have to rush to hunt a small handful of transformations that escaped, before they cease to exist.

29 :03x03 - Inferno

Ben, Gwen and Kevin discovers Vulkanus plans on drilling down to the core of earth.

30 :03x04 - Fool's Gold

31 :03x05 - Simple

32 :03x06 - Don't Fear the Repo

Alien Repo men come to take Ship back to his previous owner.

33 :03x07 - Single Handed

34 :03x08 - If All Else Fails

35 :03x09 - In Charm's Way

Charmcaster returns and flirts with Kevin in an attempt to steal all of Gwen's powers.

36 :03x10 - Ghost Town

Vilgax returns with a surprise. He needs Ben's help to save his home planet, from Ghostfreak!.

37 :03x11 - Trade-Off!

Kevin and Darkstar go after an old artifact that will fix both of their problems, by sealing their respective powers.

38 :03x12 - Busy Box

Kevin, Gwen and Ben find an alien box that turns into robots.

39 :03x13 - Con of Rath

Ben is asked to deliver Zaw-Veenull, the Luodan ambassador's, crown price Tiffin to Jarrett. However, when the Omnitrix malfunctions, Ben is turned into an Appoplexian named Rath.

40 :03x14 - Primus

While fighting a Techadon robot, Ben, Gwen, and Kevin find themselves transported by the Omnitrix to a planet named Primus. They find out that they are not alone on the planet and Vilgax is there trying to stop the Omnitrix.

41 :03x15 - Time Heals

Despite being warned, Gwen travels back in time in order to prevent an accident that turned Kevin into a monster. When she returns to the present, Gwen finds that her travel in time caused a ripple of events that led to Hex ruling the world. Now, she must fix the damage she created.

42 :03x16 - The Secret of Chromastone

Tetrax visits Ben while he is sick, but shocks Ben when demands a Chromastone from him. Ben's situation gets worse when Vilgax shows up and is after the same thing.

43 :03x17 - Above and Beyond

The Plumbers' Helpers have to save Grampa Max-- from Ben??

44 :03x18 - Vendetta

Kevin comes home to find that someone has broken in, and has Ben and Gwen work with him to find out who did it and why. They end up crossing paths with Ragnarok who is looking for a special key, which makes Kevin set out to stop him from getting the key.

45 :03x19 - The Final Battle (1)

Paradox and Asmuth tell Ben that Albedo(from Good Copy, Bad Copy) has stolen the Ultimatrix, as well as kidnapped Gwen and Kevin. Ben has to hurry to save them and stop him and Vilgax.

46 :03x20 - The Final Battle (2)

Ben goes on to Vilgax's ship and tries to stop the invasion of Earth. Ultimately, Azmuth gives Ben the Ultimatrix.