Social and Behavior Change Communication is a vital strategy in the control of malaria. However, the effectiveness of fear appeal tactic as a preventive strategy remains uncertain. This study examined the influence of a fear appeal mobile phone-based intervention, guided by Witte's Extended Parallel Process model, on malaria prevention among caregivers with children under-five. We conducted a quasi-experimental study of a 12-month intervention using a sample of 324 caregivers from two rural districts, assigned to either an intervention or control group. The intervention group received fear appeal voice Short Message Service (SMS), once a week for twelve (12) months, while caregivers in the control group received none. The results showed that exposure to the messages was associated with an increased odds of positive attitude [adjusted Odds ratio (aOR) = 2.58; 95% CI 1.61-4.15] and behavioral changes (aOR = 2.03, 95% CI 1.29-3.19). The intervention group exhibited lower odds of defensive avoidance (aOR = 0.44, 95% CI 0.29-0.68) and message minimization (aOR = 0.51, 95% CI 0.33-0.78) compared with the control group. These findings highlight the importance of communicating health messages via mobile phones using fear appeal for improving the health behaviors of caregivers. This strategy, however, may not be useful for influencing the intention of caregivers to engage in positive health practices to protect their children from malaria.