The Children's Defense Fund sponsored a "stroller brigade" march Sunday outside the state Capitol in downtown Jackson.
Activists said they want to ensure that larger numbers of children from low-income families receive publicly funded health insurance.
Meanwhile, conservatives organized a late Sunday afternoon event at the Rankin County Pavilion in Brandon. That group opposes a larger government role in health care.
The Mississippi rallies come after weekend passage of the health care bill in the House. The Senate has its own version, which has yet to come to the floor.