Officers say that the robber approached a woman who was walking south in a parking lot in the 300 block of West University Boulevard (along Robertson Avenue) around 3:09 AM Tuesday.
The robber and pointed a handgun at the victim and demanded her cell phone.
The victim gave the woman her phone from her purse without incident.
Police then say the robber got into a nearby black-colored vehicle with two other women and took off.
Police say the robber is a black woman in her early 30s.
The suspect is reportedly 5'6" tall and she weighs 100 pounds.
Officers say the woman had black hair, and she was wearing a gold shirt and black pants.
The woman also reportedly had prescription glasses on, along with either a gold tooth or braces.
Police say one of the other women in the getaway vehicle was described as slender, while the other was heavier set.
Anyone with information on the robbery should call Odessa Police at (432) 333-3641.