Researchers found that mums will spend more than £1,338 on new clothes, accessories and school uniform for their little girls – £126 more than they do on their sons.
Over the course of 18 years, that amounts to a total of £24,084 spent on a girl’s wardrobe compared to just £21,811 on clothes and shoes for boys.
This is reflected in shopping habits, as while almost half of parents said they love shopping for girl’s clothes, two thirds of those with sons hate it and just find it a chore.
A spokesman for F&F at Tesco, which commissioned the research, said: "Most parents would like to think they spend an equal amount on their sons and daughters, but it seems that parents find the girlie dresses harder to resist than boyish tops and jeans – giving girls’ wardrobes the edge over their brothers.
"Even with school uniforms, parents end up spending more on their daughters than their sons. Although while it seems parents prefer shopping for their daughters, the difference in cost could be down to them buying their sons cheaper clothes – as they are most likely to lose or break things.
"Most parents with boys will have had to replace lost school jumpers or worn out trousers, but I’m not sure as many mums of little girls will have the same problem.’’
The study, of 2,000 parents found that each year, parents will spend £212 on outfits for their daughter to wear on special occasions compared to just £170 which gets splashed out on their sons.
New tops, trousers and underwear see a further £622 spent on daughters while just £568 is spent on the same items for boys each year.
Even pyjamas, slippers and dressing gowns see those with girls part with more cash – £162 a year compared to just £141 for boys.
Things even out when it comes to the school run - shoes account for £225 for girls, while school uniform and sports kit adds another £118 to the total. Parents of boys spend £222 on shoes, with a further £111 on clothes for school and a sports kit.
More than half of those who have all boys even admitted they sometimes wander past girl’s clothes and wish they could be shopping for girl’s fashion instead.
Almost two thirds of parents also said they find it hard to resist buying clothes for their little girl, compared to just over half who said the same about their sons.
However, one in twenty parents reckon they do end up spending more on their sons, with a quarter of those putting this down to their little boys losing and breaking their clothes and shoes so often.
Another 27 per cent said their sons are more likely to get dirty so they need a bigger wardrobe.
The spokesman added: "When it comes to their boys, parents are perhaps more concerned with making sure clothing is durable and doesn’t cost the earth to replace.
“Finding quality clothing at a price that offers value for money is always a challenge for parents and that’s something we remain conscious of."