This research aims to determine the determinants of retirement security (RS) among Malaysian civil servants, identify the "inputs"-retirement literacy, retirement behaviour, and professional financial advice-and the "throughput"-attitudes toward retirement (ATR)-to reach the intended "outputs"-RS. Self-administered questionnaires were utilised to survey Malaysian civil servants regarding their RS. A multi-stage random sampling method was used to draw a representative sample of Malaysian civil servants and 361 completed selfadministered questionnaires were received from 25 government departments in 5 regions: North, South, East, West and East Malaysia (Sabah). Covariance-Based Structural Equation Modelling statistically analysed data. With a R square of 0.42, the RS model explains 42% of retirement security variances. ATR and retirement behaviour significantly influence Malaysian civil servants' RS. Partial mediation was depicted in the influence of retirement behaviour; on RS, and full mediation was shown in the influence of retirement literacy and professional financial advice; on RS. This study could help policy-makers, government, and nongovernment organisations identify Malaysian civil servants' vulnerability to unsecured retirement based on socio-economic attributes and practises. These agencies could design RS programmes for Malaysian civil servants based on retirement literacy, retirement behaviour, professional financial advice, and ATR levels.