Asthma UK is rolling out a television advertising campaign that does not ask for money in the usual way.
The advert asks viewers to call if they would like a free information card about asthma. They are then asked if they will make a discretionary one-off donation in return. They are later approached to become regular givers.
There was a week-long test of the ad in March, which the charity said brought in "significant" donations.
The 30-second ad will run on 20 channels until the end of October. It explains how sufferers fight for breath during an attack and then invites viewers to call for the free card with instructions on what to do in a medical emergency.
The test advert generated 60,000 calls, and the charity distributed 48,000 cards.
"With the test, the return on investment was ahead of the charity's history and target," said Mike Colling, media planner at MC&C, which worked on the advert.
He added that the amount raised by the test was "significant", but would not confirm the exact amount or the campaign's full target.