Army general inspector Eberhard Zorn said the forces had to "look in all directions in times of a lack of qualified personnel", such as doctors and IT specialists.
The armed forces have been beset by years of under-investment.
Germany aims to increase its military by 21,000 personnel by 2025.
It has also pledged to raise its defence budget from 1.2% to to 1.5% of its gross domestic product by 2024, in the face of criticism from President Donald Trump that it does not meet the Nato target of 2% of GDP.
Defence Minister Ursula von der Leyen said in an interview on Thursday that 182,000 uniformed soldiers were now employed by the army, a rise of 6,500 in two years. Within seven years, that should reach 203,000.
She said the army was now made up of 12% women and this year alone one in three people applying to be an officer was a woman.