Ilene went missing on Jan. 30, 1989, and each year her family recreates a 2-mile walk she took from her Dublin school, Wells Middle School, to where she was last seen on San Ramon Road and Amador Valley Boulevard.
The walk then continues to St. Raymond Catholic Church at 11555 Shannon Ave., where an ecumenical service will be held with the family's rabbi and cantor and community members will speak about Ilene and the ongoing search for her.
Ilene will turn 39 in March, her father Mike Misheloff said.
"We're glad people still remember and still help," Misheloff said.
The walk is set to begin at 7 p.m. at the school at 6800 Penn Drive in Dublin.
Misheloff said participants will carry signs, including one that says, "Help bring Ilene home."
The service will be held at about 8 p.m. following the walk.
If there is rain, Misheloff encouraged attendees to come to the service portion, but said his family, including his wife and Ilene's twin brother Brian, will participate in the walk even in wet weather.
Ilene's older brother does not live locally and will not be able to attend, he said.
Ilene vanished after she was excused early from a physical education class at her school on that ill-fated day 25 years ago.
She was last seen in a pullover polo sweater, a striped shirt, black Keds sneakers and had a dark blue backpack.
Misheloff said the annual event marking her disappearance serves as a way to "make sure everyone knows we are still looking for Ilene."
"It's a way of reminding people once a year that Ilene is still missing," he said.
The tradition of holding a vigil and service is hard on Misheloff and his family.
"It's a difficult day for us. It would be even if we didn't do anything," he said.
He said the family appreciates the ongoing support of the community and involvement in the walk and vigil every January, but said "hopefully this will be the last year this has to happen."
Dublin police are still actively looking into the case and each year receive tips about possible whereabouts of Ilene, Misheloff said.
There is a $95,000 reward available in the case. More information about the case can be found online at http://www.find-ilene.org.