Sunbeds have put a generation at greater risk of cancer, the charity says
People in their 60s and 70s in Wales are more than five times more likely to be diagnosed with malignant melanoma than 30 years ago.
Statistics from Cancer Research UK show that "baby boomers" are at far greater risk of getting the deadliest type of skin cancer than their parents were.
In Wales, 192 people in their 60s and 70s are diagnosed with malignant melanoma each year.
The statistics come as the charity launches the 2010 SunSmart campaign.
The baby boomer generation has seen the biggest increase in incidence rates of melanoma, rising from seven cases per 100,000 people in the mid 1970s to 36 cases per 100,000 now.
This age group accounts for 40% of the 482 people diagnosed with skin cancer in Wales each year.
The rates have risen most dramatically for men in this age group, who are now more than seven times more likely to be diagnosed than in the 1970s.
Cancer Research UK hopes that young people in Wales will see the impact tanning has had on their grandparents' generation and will think twice about sunbathing and using sunbeds.
Cancer Research UK's SunSmart manager Caroline Cerny said: "A change in the culture of tanning, including the explosion of cheap package holidays and the introduction of sunbeds in the '70s, means we're now seeing alarming rates of melanoma for an entire age group.
"The battle against melanoma is far from won. Today the problem threatens to get worse as teenagers continue to crave a tan on the beach and top it up cheaply on sunbeds.
"Already skin cancer is predicted to become the fourth most common cancer for men and for women in the UK by 2024.
"We must continue to try and stop this pattern of behaviour or melanoma rates in future generations will hit an all time high."
She added that melanoma is largely preventable.
"Burning is not only painful and unsightly; it's a clear sign that UV rays from the sun have damaged the DNA in your skin cells," she said.
"This significantly increases the chance of developing skin cancer and makes skin look older.
"People with fair skin, freckles and lots of moles should take extra care in the sun. But everyone should avoid the temptation to redden or burn in order to get a tan."
Melanoma death rates have more than doubled since 1973.
All councils in Wales have banned sunbeds in leisure centres and Cardiff North MP Julie Morgan has brought a private member's bill to ban under-18s from using tanning salons in Wales and England.
The SunSmart campaign is funded by the UK health departments.