People who attended the memorial included members of the local Sikh community and leaders of other religious faiths. Some held photos of the six people who were killed and police officer who was wounded.
It was last Sunday when white supremacist Wade Michael Page went on a shooting rampage before taking his own life after being shot by an officer.
"We are just trying to aware the community, aware the people, who we are if they have a question of mistaken identity or anything and also to join everybody so this doesn't happen to any other temple or synagogue or church or anything like that or to any gurdwara that is a Sikh temple," said Dr. Amrat Singh, one of the memorial's organizers.
Also Sunday, the temple in Oak Creek, where the shooting took place, was reopened with a traditional cleansing and rebirth ceremony.
The Associated Press contributed to this report.