Mood Disorder Questionnaire (MDQ) and Bipolar Spectrum Diagnostic Scale (BSDS) are used to screen patients with bipolar disorders and have been examined in some psychiatric settings. The present study aimed to assess the validity and reliability of these 2 tools on inpatients in a general hospital. In a cross-sectional study in 2011, a total of 207 inpatients admitted to different wards of Rasoul Akram hospital, Tehran, were selected by systematic random sampling. Demographic questionnaire, MDQ, and BSDS were completed. Also, Structured Clinical Interview for DSM-IV axis I disorders (SCID-I) was performed for all participants within 72 hours. The SCID-I was used as the gold standard of psychiatric diagnoses to identify the predictive validity of the 2 screening tests. Sensitivity and specificity indices were identified using Roc curve. The 2 screening tools were recompleted by 20% of the patients (n=43) after 3-7 days to measure test-retest reliability using paired t test and correlation between measures in 2 separate occasions. In this study, 101 female and 106 male (m=36.9±15.5 yrs.) patients were entered the study, of them 56 (32 males) had bipolar disorder according to SCID-I. The most common bipolar disorder was bipolar disorder type II (9.7%). Pearson's test showed a high test-retest reliability for both MDQ (r=0.72, p<0.001) and BSDS (r=0.77, p<0.001). For MDQ, the scores 5 (sensitivity=0.60; specificity=0.73) and 6 (sensitivity=0.56; specificity=0.77) were the best cutoff points. Positive and negative predictive values for the mentioned cutoff points were 0.45 and 0.83 (for the score 5) and 0.48 and 0.82 (for the score 6), respectively. The best cutoff point for BSDS was 11 with the sensitivity, specificity, and positive and negative predictive values of 0.74, 0.69, 0.47, and 0.87. The Persian versions of MDQ and BSDS have acceptable validity and reliability to screen Persian patients with bipolar spectrum disorders in a general hospital.