Osteoporosis has been recognized as a major public health problem by healthcare providers in Saudi Arabia. The present study examines the osteoporosis knowledge, health beliefs, and some of the life habits in two different Saudi women's groups (with family history, and without family history), to find the association of their knowledge and health beliefs with their preventive practice. This is a descriptive cross-sectional study conducted among a convenience sample of 288 young age (20 to 40 years) women attending the health centers in Al-Hassa, Saudi Arabia. Both groups had an inadequate daily calcium intake with a significant difference between them. The women without family history had low mean of knowledge (8.9 ± 2.7) compared with family history group (9.3 ± 2.7) with a significant difference (p = 0.04). Based on the Osteoporosis Health Belief Scale (OHBS) subscale mean score, the perceived susceptibility and perceived severity were lower in women without family history with a significant difference between the groups (p = 0.02, 0.00; respectively). The family history group had lower mean score barriers of calcium intake and exercise with a significant difference between groups (p = 0.017, 0.013; respectively). Statistically significant correlation was found between calcium intake and OHBS subscale perceived susceptibility, perceived severity, perceived benefits of calcium intake and exercise, and perceived barriers of exercise only for the family history group. This study indicates inadequate daily calcium intake, with moderate knowledge of osteoporosis in Saudi women and highlights the need for diet and life habits interventions to improve calcium intake and exercise, which may help to reduce the burden of osteoporosis in Saudi Arabia.