It is important for you to register for the classes you need as soon as registration opens for you. As you probably know, registration priority is computer enforced at SDSU. Seniority determines where you are in the registration queue, with graduate students and freshman usually given priority – and then seniors, juniors, sophomores in that order. Students who are affiliated with certain groups are given priority registration. This is all controlled by the Registrar’s office and we (in the Bioadvising office) don’t have any way of changing anyone’s registration date.
If you are shut out of a course that you need (especially lower division), check the class schedule daily. If demand is high and the course fills quickly, a lecture class may be moved to a bigger room, opening more seats. For multi-section courses, an extra section is sometimes opened up. (But not during summer session.) However, over the past few years, the university administrators have not been able to add additional sections very often because of budget cuts.
Other coursework options?
If you the course you want is full and you cannot register, first consider other options. Is this a required course or optional? Will it be offered next semester? Can you fill your schedule with other necessary classes? If you are a Biology or Microbiology major, the best way to answer these questions is to visit the Bioadvising office. You can email, call or walk in to meet with the advisor in LS 135. Note that during the busiest times of the year (two weeks before classes start until the add/drop period ends), we advise students on a first-come, first-served basis, and can't make appointments for specific times. So it is best to visit us as early as possible.
If you are not a Biology major, you should meet with the major advisor from your department.
You may need to "wait list" a course, which is the term used for the process of trying to enroll in a closed course under two situations. First, you may decide to enroll in a particular course after registration has ended, but before the add deadline. Second, you may wish to enroll in a course that is already full.
A detailed description of the wait list process is available here: Wait Llist Registration Made Easier
Open University Students
If you wish to take courses at SDSU and are not officially enrolled in a graduate or undergraduate program, you may enroll in those courses through the College of Extended Studies "Open University". See the instructions for Open University Registration on this web page.
As an "Open University student," you may not register for a course until the professor has verified that all regularly matriculated (full time) students have enrolled. That will limit your selection in some courses that fill early because they are small and/or heavily utilized by full time students. You can check the online schedule of classes to see the number of seats available for both this semester and past semesters.