The horrific moment was caught on camera,as gasps of horror are heard from neighbours in Energodar, Ukraine.
The tragedy took place in broad daylight and the footage was posted online.
According to Mirror Online, the video shows the 45-year-old mother, named as Svetlana Sheleveyster, standing on the balcony of her ninth-floor flat holding the body of her 12-year-old daughter.
She can be seen struggling under the weight of the unnamed girl before she appears to throw her over the side on purpose.
Reportedly she tried to flee the flat, but police – alerted by neighbours – caught her and arrested her
It is claimed she smothered her daughter before throwing her down to the ground.
It is rumoured the mum, a teacher, had suffered with mental health issues recently but had not sought help.The 45-year-old suspect has an older daughter and husband, but they were not home at the time.
She remains in police custody charged with murder.