Multi-story reinforced concrete tunnel form buildings are one of the common structural types in regions prone to high seismic risk due to the buildings inherent earthquake resistance and ease of construction. Despite their good performance during earthquakes in 1999 in Turkey, and abundance of such structures scattered worldwide, current seismic codes and design provisions provide insufficient guidelines for their seismic design. As a compensatory measure, a series of modal and nonlinear static analyses are conducted by emphasizing the characteristic dynamic behavior of tunnel form buildings including impacts of wall-to-wall and wall-to-slab interaction and effects of torsion and wall-openings on the load transfer mechanism and seismic performance. A new formula for explicit determination of their fundamental period is developed in addition to a recommended response reduction factor and reinforcement detailing around shear-wall openings. (C) 2004 Elsevier Ltd. All rights reserved.