Firefighters rushed to the scene in the city centre where flames could be seen bursting from windows of the 14-story residential building where the blaze apparently started.
Residents could be seen waiting for rescue on balconies, and firefighters used a crane to rescue two residents from one of the balconies.
Soldiers from Spain's Military Emergency Unit also were deployed and medics set up a large tent to tend to the injured on the scene.
The fire sent clouds of black smoke billowing skyward that could be seen from afar.
Spain's weather agency, Aemet, reported winds of up to 60km/h at the time.
The fire began in the early evening and spread to an adjacent building, state news agency Efe reported.
Initial emergency service reports said there were at least 13 people injured with fractures, burns and smoke inhalation.
The 13 included six firefighters.
It was not immediately clear how many people were in the buildings or how many were rescued.
Spanish Prime Minister Pedro Sánchez posted a tweet on the X platform saying he was "shocked by the terrible fire in a building in Valencia" adding that he had offered the city "all the help that is necessary".
"I want to convey my solidarity to all the people affected and recognition to all the emergency personnel already deployed at the scene," Sánchez said.
