Abstract: A dual axis bioreactor system wherein a bioreactor vessel is mounted at its longitudinal axis to a horizontal axle with the bioreactor vessel thereby being rotatable about its longitudinal axis. The horizontal axle is rotatably mounted to a vertical shaft with the vertical shaft rotating the horizontal axle in a horizontal plane. A gear system limits the rotation of the bioreactor vessel to one rotation about its longitudinal axis for each revolution of the bioreactor vessel about the vertical shaft. A flexible, multilumen conduit is affixed to the base of the bioreactor vessel at the longitudinal axis to provide fluid communication with the bioreactor vessel. The rotation rate of the vertical shaft is carefully controlled to reduce any centrifugation effects upon the contents in the bioreactor vessel while providing mixing therein.