In the current study, a total of 1015 prescriptions were analysed over a one year period, out of which 415 (40.88 %) showed different types of prescription errors. We analysed the prescription errors into 4 categories- indication, dosing, kinetic and combination errors. Use of an irrational FDC was considered as an error as it reflected ignorance on the part of the practising doctors about the rationality of the combination they prescribed. Interestingly, the study revealed a maximum of combination errors thus confirming our assertion that doctors do not give proper thought when they prescribe FDCs. Often it is seen that the medical representatives misguide the doctors into the authenticity and rationality of a wrong FDC and due to the lack of knowledge the medical practitioners often fall prey and are liable for prescribing such irrational FDCs. This amounts to a rise in knowledge–based errors in clinical practice.