Despite Debenhams carrying out over one million bra fits a year, the majority of women would rather spare their own blushes than go and get measured for a bra that does the job.
The findings came from a survey by Debenhams, which showed that going topless, feeling uncomfortable and being made to feel embarrassed came out as reasons women felt reluctant to go for a professional bra fitting - all three are completely false.
Debenhams head of lingerie buying and design Sharon Webb commented: "The results of our survey were shocking - it's astounding how many myths there are surrounding how a bra fit works.
"What's more a woman can go from a 36B to a shapely 32D in a matter of minutes by getting a good bra fit - no drastic surgery required."
Britain's first lady of lingerie, designer Aliza Reger added: "Fit is of paramount importance, a great fitting bra makes you look good on the outside and feel fantastic on the inside.
"It really is staggering how many women get it totally wrong. There really is nothing worse than an unsupported bust or spilling over the top of an ill-fitting bra."
Until the 22nd May 2011, the hundreds of expertly trained lingerie fitters at Debenhams are fitting as many women as possible, to raise awareness of the importance of wearing the right sized bra and the dramatic difference it can make to a woman's figure.
Women can take advantage of the free bra fitting service in all Debenhams stores, and those who do so during May will receive £5 off bras when they are fitted.