More than 10,000 of the country's 53,000 headteachers are due to retire over the next 10 years - in some regions, such as Hesse, nearly half of the top posts will fall vacant.
But the association of headteachers claims that the combination of little extra money and still heavy teaching loads means many teachers are shying away from applying for headships. Klaus Cammans, the association's chair, said that education ministers were underestimating the impending crisis.
Senior teachers earn an average DM 8,000 (Pounds 3,330) gross per month. But promotion to headteacher brings only an extra DM 150 to 400 (Pounds 62-Pounds 167). For this they are expected to administer the budget, organise personnel, curricula and extra-curricular activities, lead parent councils, and gather statistics. And their teaching burden can be up to 22 hours a week in smaller schools.
As a result, headteachers work long hours and give up holidays to keep up with the job. A survey for the state of North Rhine-Westphalia revealed that most heads put in 48 hours a week, although they only get paid for 38.5 hours.
The headteachers also claim that the mostly voluntary management training is not good enough. And once in the post, they do not have enough autonomy from state politicians to make decisions.
Herr Cammans, a headteacher in Lower Saxony, said: "We cannot even employ our own staff, although in my case the education authority is 150 kilometres away."
But politicians are playing down the problem. Rosemarie Raab, president of the national conference of education ministers, said teachers' ambitions meant they would not be deterred from becoming heads.