Abdirahman was last seen on Beswicke Court this afternoon around 1:40pm.
Police and family hold concerns for him due to a medical condition requiring medication.
The 17-year-old is described as African in appearance, 185-190cm tall with a medium build and black hair.
Abdirahman is known to frequent the Dandenong and Springvale areas.
Anyone who sees Abdirahman is urged to contact Dandenong Police Station on (03) 9767 7444.