Lead contamination in soil represents a serious threat to soil-dwelling invertebrates. Despite the ecological importance of Collembola, their responses to heavy metal stress in tropical environments remain insufficiently explored. This study investigated the physiological stress response and lead accumulation in the soil microarthropod Cyphoderus javanus under chronic exposure to sublethal concentrations of lead-contaminated garden soil under tropical conditions. Individuals were maintained in an environmental chamber at 28 ± 0.5 °C, with soil moisture regulated using distilled water.Lead toxicity was evaluated by assessing moulting frequency, reproductive output, survival, and the bioconcentration factor (BCF). The results demonstrated concentration-dependent physiological stress, evidenced by reduced moulting frequency, decreased reproductive output, and lowersurvival at increased lead concentrations. BCF analysis indicated a time- and concentration-dependent increase in lead accumulation, although the relationship was not strictly linear, particularly at lower exposure levels. Nevertheless, lead bioaccumulation was significantly elevated with prolonged exposure and higher concentrations. These findings highlight the sensitivity of soil Collembola to lead contamination and underscore the ecological risks posed by heavy metal pollution. The study emphasizes the need to protect soil fauna to maintain ecosystem stability and soil health, which are essential for sustainable terrestrial ecosystem functioning.