Learn Portuguese phrases. Visit the International Vegetarian Union website where you can find useful vegetarian phrases in Portuguese. Commit the phrases to memory, or jot them down on an index card to communicate your dietary needs.
Visit a health food shop when you're in a larger Portuguese town. Health food chains, such as Celeiro Dieta, offer vegetarian eateries in some of their locations. Stock up on nondairy milks, cereals and vegetarian or vegan nonperishables if you plan to visit smaller towns where vegetarian eateries are rare.
Browse the supermarket and create your own vegetarian or vegan meal. Pick up some fruit, bread, olives, cheese and yogurt. Larger supermarkets such as Pingo Doce have a health food aisle where you can stock up on your vegetarian essentials.
Use websites such as happycow.net or vegdining.com to find vegetarian and vegan dining options in the towns that you plan to visit. Both websites provide addresses, phone numbers and websites of the restaurants, as well as useful reviews written by customers.
Order an omelet, cheese plate, salad, vegetable plate or bread and olives when you're at a traditional Portuguese eatery. Ask your server if there are animal products in the soups, as most vegetable soups in Portugal tend to use chicken, beef or pork broth.
Visit a farmers market--they can be found in most Portuguese towns. Enjoy the locally grown fruits, veggies, freshly baked breads and local cheeses for a simple meal.
Do a search for vegetarian- and vegan-friendly bed and breakfasts on websites such as the euroveg.eu. The listed accommodations offer home cooked vegetarian/vegan meals.
Another option is to find an accommodation that includes the use of a kitchen. Prepare your own meals using local ingredients.
Eat at ethnic restaurants for a change when you're in a larger town. Try the Italian, Chinese, Lebanese or Indian eateries–they may be more likely to offer more dishes made without animal products.