Parafilm consists of a flexible film, available in several different lengths and widths. It is commonly used for sealing or protecting vessels (such as flasks or cuvettes). It is stretchable, moldable, waterproof, odorless, thermoplastic, semitransparent and self-adhering. It is also used to further seal a lidded container against moisture for long term storage.

Since it is a thermoplastic, Parafilm is not safe for use in an autoclave.  Horticulturalists have discovered that Parafilm is well-suited for grafting applications. Several grafting styles call for wrapping a graft to hold it together, and sealing it to prevent drying; parafilm does both. In this context Parafilm is also known as grafting tape.

Entomologists have used Parafilm as a membrane to feed blood-feeding insects such as mosquitos reared in the lab.