This aim of this study was to assess the degree to which the doctors of a public sector hospital in Karachi adhere to medical ethics during their consultations. A cross-sectional study was conducted in Civil Hospital, Karachi, Pakistan, during April-June 2010. 337 patients from Out Patients Departments (OPDs) and wards were recruited through consecutive sampling. A pre-tested structured questionnaire was administered to the participants and they were asked about their demographic profile, and their doctor's practices regarding obtaining informed consent, respecting privacy and confidentiality, and treatment modalities. Written informed consent was taken from all the participants. Data was analysed using SPSS version 16.0, and a p-value of < 0.05 was considered as statistically significant. The mean age of the study population was 38.4 ± 15.0 years. There was an equal ratio of males and females. Our study showed that informed consent was obtained from 66.4% of patients. 56.9% of patients responded that they were not informed about the side effects of the prescribed medicines. 74% females were satisfied with the privacy maintained during the consultation. 64.8% were assured of the confidentiality of their information. Regarding advertisement by doctors, 46.5% of patients said it should be done. There has been a marked improvement as compared with the previous practices of biomedical ethics by the doctors of this public sector hospital. However, awareness sessions should be conducted to update / improve the knowledge of ethics among doctors to help them translate their knowledge into practice.