Do I need any especial vaccination in order to travel to Oaxaca?
No, the sanitarian authorities of the State of Oaxaca do not ask visitors to present any vaccine certificate. However, it is regarded as a zone of moderate risk for malaria for being a tropical area; hence, you need to take certain precautionary measures. The best thing to do is to consult your family doctor.

Is potable water reliable?
Oaxaca and its main tourist destinations provide potable water by means of a utility system; although, an advised traveller amounts for a safe traveller, meaning it is recommendable to drink bottled or purified water only, especially in you are in a rural area.

What precautions should I take regarding food?
Avoid eating at the so-called paraditas (street stalls) or at seemingly unhygienic places.
Likewise, bear in mind that the exquisite cuisine of Oaxaca is quite seasoned; therefore, it is suggested to eat moderately during your first days here. Prefer light dishes until your stomach gets used to our traditional seasoning and to hot tastes.
If in spite of all these precautions you were to suffer a stomach problem, do not get too worry for this is a rather common discomfort among travellers, and it usually carries no further consequences.