The Sciencenter grew out of the vision of community volunteers Debbie Levin and Ilma Levine who sought to expand upon the "Science Discovery Room Program" they developed with Beverly J. Martin at Central Elementary School (now called Beverly J. Martin Elementary School) in the 1970s-1980s.

In 1982, an ad was placed in the Ithaca Journal inviting any individual interested in starting a community science center to meet at the local public library.

Volunteers built exhibits, a small museum store was added, and schools were invited to bring classes for hands-on programs.

When the Sciencenter was forced to close its Tioga Street site to make way for a new county building, Ithaca Center Associates offered temporary space.

The Sciencenter relocated to the Center Ithaca complex during 1989 and in 1990 closed its exhibit space to focus on the task of building a permanent home.

Leathers proposed the Sciencenter be built by members of the community – including businesspersons, secretaries, store clerks, teachers, bricklayers, electricians, university professors, doctors, grandparents, and children.

In October 1990, the board, under chair Bruce Thompson, hired registered professional engineer and geologist, Dr. Charles Trautmann, as executive director.

The project was announced in February 1991 at a party at Rock Stream Studios, then at 235 Cherry St. in Ithaca, that was attended by 500 individuals and highlighted by presentations by Mayor Benjamin Nichols, Assemblyman Marty Luster, State Senator Jim Seward, Congressman Matt McHugh, Cornell President Emeritus Dale Corson, Nobel Laureate Hans Bethe, and Cornell astronomer Carl Sagan.

Cornell fundraiser Sherri Bergman, anxious to join the challenge of creating a community-built science center, was hired to help with the project.

To accommodate this growth, the Sciencenter leased an adjacent brick building from the City of Ithaca to provide 2,000 square feet (190 m2) of program space.

In 1996, the City gave this building and the other half of the 600 block of First Street to the Sciencenter for $1 following an intense year-long lobbying effort by executive director Charlie Trautmann and Ithaca Common Council member Susan Blumenthal.

The Sciencenter in Ithaca features 250+ fun, hands-on exhibits, educational programs, an outdoor science playground, a seasonal 18-hole Sciencenter Mini-Golf course, a Tidepool Touch Tank with live marine animals, an animal room, and an area designed for kids ages 4 and under with its own playground.

The Sciencenter's first major solo NSF grant was called Tech City and led to the development of a 3,000-square-foot (280 m2) exhibition that began a national tour in 2003.