South Wales PCC Alun Michael is backing ChildLine's Zipit campaign to help teenagers refuse requests to share explicit images of themselves.
A Zipit mobile phone application offers advice for parents and children.
About six out of 10 children aged from 12 to 15 are thought to own a smartphone.
The charity ChildLine said "sexting" - the sending of intimate images or videos by mobile phone or online - had become so common "it is considered mundane".
The Zipit campaign is run jointly with the NSPCC (The National Society for the Prevention of Cruelty to Children) and the Internet Watch Foundation.
A new Zipit phone app also offers advice on safe online chatting and on what young people should do if they feel threatened or if an image becomes public.
The free app offers users a choice of what the charity says are "witty responses" youngsters can send when asked to share an image.
Mr Michael, who is responsible for the policing priorities of the South Wales force, welcomed the campaign.
Alun Michael says the campaigns allows parents to be 'more in tune' with the problem of 'sexting'
He said: "The explosion of the numbers of mobile phones with cameras has only been relatively recent.
"It is certainly something that parents did not have to contend with when they were young, so it can be difficult to provide the right advice and support to their children.
"This campaign comes at it from both angles - providing young people with an app which offers advice on how to engage in safe chat and the dangers of sending sexual images, and providing parents with helpful advice, so they can be more in tune with the problems that can arise."
Does anyone think this will work?
In June this year, Mr Michael said internet providers around the world had to "wake up" over images that show child sex abuse.
He spoke out in the wake of the abduction and murder of five-year-old April Jones by Mark Bridger in her home town of Machynlleth, Powys.
Bridger's trial was told that he searched the web for child abuse and rape images.
He became the 37th person to be sentenced to a whole life term when he was convicted in May.