A survey by The Times found that the high street store charged women nearly twice as much for the same product as men.
According to the analysis of hundreds of products, the cost of clothes, beauty products and toys for women and girls is higher than the equivalent goods sold by men and boys.
Many of the UK's largest retailers, including Tesco, Botz and Amazon, have "sex discrimination" prices.
In one case, Tesco charges double the price just because ten disposable razors are pink.
In Argos, the same children's scooter pink costs £ 5 more than blue.