Before you start:
You should contact potential supervisors before you start the admission process. In natural sciences most PhD positions are dependent on sources of funding. Because of this, many open PhD positions will be publicly announced and you can apply to them officially. Applying to them and being chosen does not automatically make you a PhD student, even if you already signed an employment contract. You still need to go through the official enrolment process of the university (see Admission process).
Of course, you can also contact potential supervisors privately and ask for a position or simply for their supervision of a self-financed project.

Getting started:
If you found someone who is willing (and officially authorized) to supervise you, you can start the admission process. This is where it can get tricky, though. An official outline can be found in this PhD Handbook – Navigating your Doctorate. We offer some insight into other aspects not discussed there.

Weird rule
: Seeing as your contract is not coupled to you being a student it isn’t always advisable to enroll right away. For all European students the first 8 semesters of the PhD studies are free of university tuition fee (only a very small fee, the students’ union fee, must be paid). A PhD can take a lot longer than that, however. You can counteract by officially enrolling during a later period (e.g. after one year of work on your project). From experience, no one will care. The disadvantage: you will not receive emails by your doc school coordinators and you will not pop up in stats regarding the program during this period. However, you also need to be enrolled for at least 6 semesters (3 years) before your graduation.

Admission process:
All the details regarding the admission processes are outlined here (for natural sciences), here (for life sciences) and here (for molecular biosciences). Generally this process is rather straight forward. All you need to do: submit the right documents and fulfil the requirements for your respective field (e.g. holding a masters/diploma degree).
It is possible that you are required to complete certain courses to be eligible for the field of studies that you choose. This depends on where and what you studied.

Timeline after admission:
Basically, most curricula are rather similar and consist of:

  • The general degree programme duration of 3 years (although it is perfectly normal to take longer than that)
  • Courses:
    For the fields Biology and Molecular Biology at least 30 ECTS
    For the fields Nutritional Sciences and Pharmacy at least 20 ECTS
    For the fields Astronomy, Earth Sciences, Geophysics, Mathematics, Meteorology, Physics, and Psychology at least 24 ECTS
    For the fields Chemistry, Environmental Sciences, Geography, and Computer Sciences at least 12 ECTS
  • A public presentation of the intended doctoral project within the first year of doctoral studies (the date of admission counts as the beginning, not the contract). It’s called the FÖP (faculty open presentation): ask your study service center (SSC) for the specific formalities of your department.
  • Signing a doctoral thesis agreement subsequent to the public presentation
  • Do science
  • Periodical, at least annual progress reports
  • Write a doctoral thesis, which demonstrates the candidate’s ability to master academic topics independently
  • Public defense

Resources for more Information

The center for doctoral studies offers workshops and additional information (mostly booklets) for new PhD students. For issues specific to your studies program, your SSC (“Studien Service Center” + your discipline) is the best resource. They can tell you how your public presentation needs to be held and give you a doctoral thesis agreement template.