This study investigates the plant associations of firefly larvae (Coleoptera: Lampyridae) in the mangrove ecosystem of Tumpat, Kelantan. Fireflies are important bioindicators of environmental health, yet little is known about their larval ecology, especially regarding habitat and associations plant preferences. The study aimed to identify plant species associated with firefly larvae and adult display plants through field sampling using sweep nets and forceps within designated mangrove plots. Data on larval abundance relative to associations plants were analyzed along with environmental parameters such as water pH and temperature. The study found that firefly larvae predominantly associate with three mangrove plant species Volkameria inermis, Acanthus ilicifolius and Acrostichum aureum with Volkameria inermis having the highest relative larval abundance. Adult fireflies mainly utilized Sonneratia caseolaris as display plants. These findings highlight the ecological specificity of firefly larvae to certain low-elevation host plants, emphasizing the importance of these plants in sustaining firefly populations. The results provide valuable baseline data for conservation management of fireflies and their mangrove habitats, underlining the need to protect and restore critical plant species to maintain ecosystem health and biodiversity in Malaysian coastal regions.