Objectives The prevalence of antimicrobial resistance (AMR) is rising globally as well as in Malaysia. AMR can lead to difficulty in the treatment of chronic infection if being neglected. This study aimed to assess the level of knowledge and attitude about antibiotic usage and AMR. Methods A cross-sectional study design was carried out at the Hospital Kuala Lumpur (HKL), Malaysia, where participants were recruited by using the non-probability convenience sampling from the six orthopaedic and four surgical wards. A self-administered questionnaire was used to collect the required data which were then analysed by using SPSS. Key findings A total number of 390 adult Malaysians (286 from orthopaedic wards and 104 from surgical wards) were involved in the study. This study showed that the level of knowledge and attitude about antibiotics among the majority of respondents were moderate. However, their knowledge regarding AMR was very low (i.e. lack of knowledge). In contrast, the majority of them (69.8%) showed a positive attitude towards antibiotics. Statistical analysis of data revealed that the level of knowledge of AMR was significantly associated with gender, age, race, marital status, educational level and knowledge about antibiotic resistance terms (P < 0.05) while respondents’ attitude towards antibiotic usage was significantly associated with gender, race, marital status and education level (P < 0.05). Conclusions It was necessary to formulate and develop strategies to improve the knowledge and awareness about antibiotics and AMR among health professionals. These might help them to improve their skills in delivering health information to the patients through a proper counselling technique.