Pgraf is a portable graphics package for the presentation of scientific data. The package is designed to operate on the simplest of graphics devices, with implementation on a new device requiring only the creation of a small set of low level subroutines. The package is written in the C language, with function calls restricted to the standard input-output and math libraries. However, the graphics is accessible from both C and Fortran 77. The functions provided include simple graphing, contouring of two dimensional fields, and perspective viewing of three dimensional wire frame structures.