Early postnatal brain tissue can be cultured in viable and healthy condition for several weeks with development and preservation of the basic cellular and connective organization as so-called organotypic brain slice cultures. The present study describes a simple method for stationary long-term organotypic culture for the hypothalamic suprachiasmatic nucleus (SCN). Hypothalamic brain slices from 1-12 day old mice were maintained in culture at the interface between air and culture medium. These slices were supported by Millicell filters without need for any strategies to promote adherence and incubated in Petri dishes. This model of organotypic slice culture was characterized by the simplicity of handling, high yields of viable and thin slices which remain 1-3 cell layers thick. It can be used to make organotypic slices from a range of ages, other parts of the brain and other rodent species.