As a foreign student you must prove adequate knowledge of the German language in order to study in Germany.
As a general rule, you will have to take the German language proficiency test -
DSH (
Deutsche Sprachprüfung für den Hochschulzugang ausländischer Studienbewerber) or the
TestDaF (
Test Deutsch als Fremdsprache für ausländische Studienbewerber).
In some cases, you might be exempted from the
DSH or
TestDaF, for example:
for a single semester periods of study in Germany (some institutions allow 2 semesters)
if you hold a higher education entrance qualification (
Abitur) from a recognised school (in Germany or abroad) at which German was the language of instruction
hold the Goethe-Institute's minor or major German Language Certificate (
Kleines/Großes Sprachdiplom) or advanced level 'Central Advanced Language Test' (
Zentrale Oberstufenprüfung)
if you hold the 'German Language Certificate, Level II', of the 'German Standing Conference of Ministers of Education and Culture' (
Deutsches Sprachdiplom - Stufe II - der Kultusministerkonferenz).
If you are required to take the DSH you will probably have to take the exam at the institution you're planning to study at in Germany.