  Quark stars are terrestrial laboratories to study fundamental physics at
ultrahigh densities and temperatures. In this work, we investigate the internal
structure and the physical properties of quark stars (QSs) in the Rastall
gravity. Rastall gravity is considered a non-conservative theory of gravity,
which is an effective gravity theory at high energy density, e.g., relevant to
the early universe and dense, compact objects. We derive the hydrostatic
equilibrium structure for QSs with the inclusion of anisotropic pressure. More
specifically, we find the QS mass-radius relations for the MIT bag model. We
focus on the model depending on the Rastall free parameter $\eta$ and examine
the deviations from the General Relativity (GR) counterparts.
