We describe a method for adherence and culture of murine Pneumocystis carinii in mink lung cells (MiCl1) grown on vertical supports. The vertical cultures were infected with P. carinii; the surrounding medium and inoculum were stirred to ensure circulation and contact with MiCl1 cells. When compared with conventional horizontal culture, the vertical method offers a more suitable system for assessing P. carinii adherence. This approach has proved suitable for quantitative evaluation of P. carinii adherence to MiCl1 cells in the presence of inhibitors.