The Malay apple (Syzygium malaccense (L.) Merr. L.M. Perry), a minor fruit crop in the Myrtaceae family, is gaining popularity due to its attractive colour, shape, appearance, thirst-quenching appeal and nutritional value. However, large-scale cultivation is constrained by the scarcity of quality planting materials, as the species predominantly relies on seed propagation. This study aimed to identify the optimal Indole-3-Butyric Acid (IBA) concentration for the vegetative propagation of Malay apple using hardwood and softwood cuttings. The experiment was conducted at Uttar Banga Krishi Viswavidyalaya, Cooch Behar, West Bengal, using a Completely Randomized Design (CRD) with 6 treatments: T1 (control), T2 (IBA 1000 ppm), T3 (IBA 2000 ppm), T4 (IBA 3000 ppm), T5 (IBA 4000 ppm) and T6 (IBA 5000 ppm). Each treatment included 60 cuttings (30 hardwood and 30 softwood) collected from 8-year-old trees. Cuttings (15 cm long with 3-4 nodes) were treated with the respective IBA concentration and planted in poly bags containing a 1:1:1 mixture of farmyard manure, soil and sand. The cuttings were maintained under polyhouse conditions for 120 days. Recorded parameters included sprouting percentage, days to sprouting, sprout length, number of roots, days to rooting, leaf number, root length and biomass. Data were analyzed using ANOVA and the LSD test in SAS (Version 9.3), with normality assessed by the Kolmogorov-Smirnov test. Results demonstrated that IBA at 3000 ppm (T4) significantly enhanced all growth parameters, increasing rooting percentage by 127 - 130 % and survival rates by 104 - 164 % compared to the control. These findings establish 3000 ppm IBA as the optimal concentration for the successful propagation of Malay apple.