The first happened just before 7:00 p.m. Thursday in the 4500 block of Girard Avenue near Belmont.
Police say a man in his late twenties was riding a dirt bike west on Girard when he hit the median and lost control.
Medics took him to the Hospital of the University of Pennsylvania where he died a short time later.
Seven minutes later and several blocks away, a 27-year-old man was killed when his motorcycle collided with a red Dodge Durango.
Police say the driver of the Dodge was making a left turn from the northbound side of Belmont Avenue onto Parkside Avenue when the accident happened.
The victim was taken the Hospital of the University of Pennsylvania and pronounced dead a short time later.
Both crashes are under investigation.