The designer is selling off more than 600 items from her own wardrobe in aid of the charity mothers2mothers.
In a video posted on theoutnet.com, the website hosting the unique sale, Victoria explains, "Every single piece that I have put in to be sold brought back a lot of memories, a lot of really, really happy memories of myself and David, of myself and the children, of different events that I've been to.
"And a lot of these pieces have been made especially for me by the designers. These haven't all been bought off of a shelf."
The mum-of-four continues, "People have asked aren't I keeping a lot of these pieces for Harper. I'm keeping a few pieces, but for me it was more important to raise money for this charity. As a woman, we have a responsibility to really help and support other women, to do what we can do to help."
Some of Victoria's most iconic pieces have been included in the sale; from the fluorescent Roberto Cavalli gown she wore for her and David's pre-World Cup party in 2006, to the white Dolce and Gabbana dress she wore to the MTV Music Awards in 2003.
All proceeds will be donated to mothers2mothers – a non-profit organisation that employs, educates and empowers women living with HIV.
Victoria visited the charity's base in South Africa earlier this year, and was moved to show her support.
"After spending just a few days with these remarkable women and learning more about the charity from (founder) Mitch (Bessen) and his lovely wife Annie Lennox, I wanted to do as much as I could," the star added. "It really was a life-changing experience; I've never experienced anything like it."
The sale - which includes hats, coats, shoes, bags, jewellery, designer ready-to-wear, costume pieces, skiwear, coats, and evening dresses - will take place from August 20-25. Prospective buyers will need to register on the website for the chance to shop Victoria’s collection.