Aims: Proteus species are implicated as serious causes of various human infections. Imipenem has been used to treat infections caused by these organisms. However, Proteus spp. are known to have reduced susceptibility and have elevated minimum inhibitory concentration (MIC) towards imipenem. The aim of this study was to determine the prevalence of Proteus species with reduced susceptibility to imipenem and the antibiotic susceptibility pattern for each Proteus species. Methodology and results: A total of 204 Proteus isolates were collected from routine samples. All isolates were identified by using VITEK® 2 GN ID card. Antibiotic susceptibility tests were done by using disc diffusion method and imipenem E-test. While 5.9% of the Proteus isolates showed reduced susceptibility towards imipenem by disc diffusion, only 1% (2 out of 204 isolates) has reduced susceptibility by E-test. Conclusion, significance and impact of study The prevalence of Proteus species with reduced susceptibility to imipenem is still low. The imipenem zone diameter does not truly reflect the MIC value and thus, in any isolates which are tested to have reduced susceptibility or resistant to imipenem should always be followed by imipenem MIC method.