Virtually all the larger restaurants downtown will have vegetarian options, but I can't think of any "pure" vegetarian restaurants in the downtown area.

Of course there are numerous Asian restaurants all over town where it's no problem, and some excellent "true" vegetarian restaurants in the neighborhoods, but those would require bus trips or taxis. With a week, however, you should have no problem finding your way around.

From downtown Plum Bistro, on Capitol Hill, is the most accessible of our good vegetarian restaurants. It is at 1429 12th Avenue. Take the #10 bus at 4th and Pine and get off at 12th Avenue: http://www.plumbistro.com

Carmelita (like Plum) has a Zagat food rating of 25: http://www.carmelita.net

HTTY

Correction: Take the #10 at 4th and Pike and get off at 12th Avenue and Pine.

As Gardyloo said, most of our restaurants have non-meat offerings. You might like this place: http://www.thepurplecafe.com/menus.html

HTTY

If you want to cook for yourself you can buy at the Pike Place Market and walk across the street to the Green Tortoise Hostel.
http://www.greentortoise.net/
I like cooking for myself at hostel kitchens.

Thanks for the help.
Went to Purple Cafe the first night....OMG delicious!! Braised beets appetiser, Washington red wine flight, roared veggie pizza (no cheese).
The next night we tried the Plum Vegan Bistro (Tempeh Vermouth: a vermouth marinated tempeh with an olive sauce, served with broccoli and mashed potatoes.) Vegan fine dining, but a casual/modern/cool venue. it was sooo good!