|"No. 20's Defiant Smile… The Secret of Doctor Gero"|
|Rōmaji||Nijū-Gō no Futeki na Warai… Dokutā Gero no Himitsu|
|FUNimation||The Secret of Dr. Gero|
|Corresponding edited Z episode numbering||115|
|Corresponding Kai episode(s)||DBK061 & DBK062|
|Manga||Chapters #343, #344 & #345|
|Japanese||March 11, 1992|
|English||September 20, 2000|
"No. 20's Defiant Smile… The Secret of Doctor Gero" (２０号の不敵な笑い…ドクターゲロの秘密, Nijū-Gō no Futeki na Warai… Dokutā Gero no Himitsu; FUNimation "The Secret of Dr. Gero") is the one hundred thirtieth episode of the Dragon Ball Z anime.
Finally becoming a Super Saiyan, Vegeta easily defeats Android 19, but 20 has escaped to come up with a new plan. Vegeta and the others look for the diabolical Android, but it won't be easy.