Professor catedrático: equivalent to full professor
Professor associado: equivalent to associate professor
Professor auxiliar: equivalent to assistant professor
Both professor associado and professor auxiliar may have Agregação, an extra degree mandatory to all applicants to the rank of professor catedrático which one can apply to usually years after the PhD (similar to the French Habilitation à Diriger des Recherches). Agregação is a two-day exam based on curriculum vitae evaluation and a public lecture, where the candidate is evaluated by secret vote by a large number of other full professors, in which the professors insert a white or a black sphere into a bag according to his or her decision.
The three ranks of professors may also be held by invited professors, according to the rank, from outside the university.
Portuguese universities still have a few other teaching staff in two ranks not holding a PhD. These two ranks were extinguished in 2009 and will vanish after all the ongoing contracts terminate in the next few years.
Assistente: equivalent to assistant lecturer (without a PhD), normally someone who is simultaneously earning a PhD and holding a master's degree; only teaches practical (or lab) classes.
Assistente estagiário: equivalent to a junior teaching assistant. It used to be the start of the teaching career until 2009 and already extremely rare to find since the Bologna agreement. They are typically graduate students and only teach practical (lab) classes.