The 37-year-old actress and humanitarian wrote about the procedure in an article entitled My Medical Choice in the New York Times. She said she had the operation for the sake of her children, after being informed that she had an 87 per cent chance of getting breast cancer, and a 50 per cent chance of ovarian cancer.
"I decided to be proactive and to minimise the risk as much I could," she wrote, revealing that she began the procedure in February, and that it was completed by the end of April.
Angelina said she wanted to reassure her own children that she would not be taken away from them in the same way her mum was taken from her - dying aged just 56 after battling cancer for a decade.
"We often speak of 'Mommy's mommy,' and I find myself trying to explain the illness that took her away from us," she wrote. "They have asked if the same could happen to me. I have always told them not to worry, but the truth is I carry a 'faulty' gene, BRCA1, which sharply increases my risk of developing breast cancer and ovarian cancer."
She said that once she 'knew that this was my reality', she made the decision to undergo the nine weeks of surgery that would result in a double mastectomy and reconstructive surgery.
"Nine weeks later, the final surgery is completed with the reconstruction of the breasts with an implant," Angelina revealed. "There have been many advances in this procedure in the last few years, and the results can be beautiful."
She said the operation had 'empowered' her, and resulted in her chances of developing breast cancer dropping from 87 per cent to under 5 per cent.
"I feel empowered that I made a strong choice that in no way diminishes my femininity," she wrote.
"For any woman reading this, I hope it helps you to know you have options."
"I want to encourage every woman, especially if you have a family history of breast or ovarian cancer, to seek out the information and medical experts who can help you through this aspect of your life, and to make your own informed choices."
Angelina praised her partner, Brad Pitt, for his support and love throughout the process, and said that her children had found nothing in the results 'that makes them uncomfortable'.
Ms Jolie has three adopted children, Maddox, Zahara and Pax, and three biological children, Shiloh, Knox and Vivienne with Brad Pitt.
Commenting on Angelina's story, Dr Richard Francis, Head of Research at Breakthrough Breast Cancer, said: "We're sorry to hear that Angelina has the BRCA 1 gene fault. For women like Angelina it's important that they are made fully aware of all the options that are available, including risk-reducing surgery and extra breast screening.
"Though Angelina decided that a preventative mastectomy was the right choice for her this may not be the case for another woman in a similar situation. We urge anyone who is worried about their risk of breast cancer to talk it through with their doctor.
"It's important to remember that BRCA gene faults are rare and in most cases are linked to family history. Thanks to great advances in research we're able to pinpoint when people like Angelina are BRCA carriers and therefore at risk.
"However we do need to continue vital research in to breast cancer so women at high risk have even more, potentially less-invasive, prevention options. At Breakthrough Breast Cancer we're dedicated to breast cancer research and ensuring better outcomes for patients in the future."