Background Local anaesthetic systemic toxicity (LAST) could be potentially life threatening. This study focused on describing the knowledge and practices of use of local anaesthetics (LA) among the doctors in Sri Lanka and the ability to detect and manage an event of LAST. Materials and methods A descriptive cross-sectional study was conducted among doctors in Sri Lanka using an online self-administered questionnaire based on AAGBI guidelines (2010). Descriptive statistics were analyzed by cross-tabulations and presented as numbers and percentages using IBM-SPSS 25. Results The response rate was 60% out of 600. Majority were males (58%) while 45% of the respondents were anesthetists. Ultrasound was used by 47.4% during LA. The majority considered total body weight for dose calculations. Around 50% of respondents identified bupivacaine as the most cardiotoxic. The majority utilized some form of monitoring and were knowledgeable on identification, prevention and initial management of LAST. Approximately 45% identified Intralipid (ILE) as the definitive treatment of LAST, out of which, 66.8% knew the correct dose and 77.2% and 26.5%, the availability and location of storage, respectively. Conclusion The basic knowledge on LAST was satisfactory among the respondents. A statistically significant difference on knowledge on maximum safe doses of LA, ILE in established LAST, its dosage and the availability was identified between anaesthetic and non-anaesthetic doctors and post graduate trainees and the rest of the doctors. Overall, significant lapses were noted with regard to the use of total body weight for dose calculations, use of ultrasound during LA administration and dosage, availability and storage of the definitive therapy, ILE, suggesting updates in these key areas.