Joshua Wakeham had been sitting on his bed looking out of the window when the blind cord became wrapped around his neck.
The little boy is thought to have struggled to free himself, but the line became more firmly stuck around his neck.
Tracey Ford, 34, found her son kneeling lifeless on his bed with the cord looped around his neck at 9pm on January 24 at the Newport home.
She phoned 999 and tried desperately to revive the toddler until he was rushed to hospital, but neither she or the doctors were unable to save him.
Joshua had only been sleeping in his own bed for two months.
His mum told the Mirror: "He had night lights and toys surrounding it. He loved Winnie the Pooh, Tigger, Lego, all the sort of things which little boys are into.
"I remember walking into his room and it looked as if he was sitting up looking out of the window.
"He loved looking out of the window and waving to people – it was one of his favourite games.
I scooped him up in my arms and he was freezing cold and as limp as a rag doll. Then I saw the cord from the window blind was wrapped around his neck.
"It was the worst moment of my life. My beautiful baby was so full of life and energy, and I just knew he was gone.
"I can't even begin to describe the feelings of helplessness and despair I felt. It's every mother's worst nightmare."
Joshua is the 11th casualty of a blind cord accident in just two years.
Heartbroken Tracey said she and her family have 'gone through hell' and said the blinds need to 'come with a safety warning or be taken off the market'.
"What I realise now is that these blinds are like giving your child a carving knife. They are absolutely fatal," she said. "In the USA, these type of blinds are banned. How many more children are going to have to die before our Government puts some legislation in place to stop this happening time and time again?"
More on Parentdish: How to safely prepare your baby's nursery
What do you think? Should these blinds be banned?