The purpose of this systematic review was to identify how the home learning environment (HLE) was measured in group design, early math intervention studies conducted in the home. Specifically, we evaluated the physical (e.g. frequency of activities) and affective (e.g. parents' beliefs, children's attitudes) aspects of the HLE. We included intervention studies conducted with parents and young children (ages 3-9 years old) that also included instruments designed to measure the HLE. We included 16 studies that used 21 HLE instruments (16 surveys, 3 interviews, 2 focus groups); we coded the characteristics of the HLE instruments, including which physical and affective aspects of the HLE the instruments measured. In most cases, parents responded to the instruments; whereas, only two studies used instruments that captured children's perspectives of the HLE. The instruments measured physical aspects more often than affective aspects of the HLE. Findings from this systematic review highlight implications for measuring the HLE and intervention development and implementation.