Suicide is a major preventable public health problem globally however, under attended in Bangladesh. It happens because of multi-factorial involvement; nevertheless, past suicidal attempt is a significant predictor of future suicidal behavior. We aimed to assess the suicidal behaviors among the patients visiting for psychiatric care in a tertiary care hospital of Bangladesh. This cross-sectional study was conducted among the patients attending at department of Psychiatry, Bangabandhu Sheikh Mujib Medical University, Dhaka, from March 2018 to February 2019. A total of 379 patients were interviewed with pre-tested semi structured questionnaire. Non probability purposive sampling was used to collect data. Data were entered into Statistical Package for the Social Sciences 16.0 software and analyzed Among the 379 respondents, 197(52%) were male, 52.5% were married. Mean±SD age of the respondents was 29.94±11.32 year ranging from 18 to 75 years. About 24% percent of the respondents had family history of mental illness, 4% had family history of completed suicides. Prevalence of life time suicidal ideation among the patients was found as 32.5%, one-year prevalence rate 26.4%, one month 17.2% and within last two days it was found as 11.3%. The rate of suicidal plan was 14.0%, preparation 10.0% and attempt was 7.4%. Mean±SD age of onset of suicidal ideation was 24.33±8.9 year ranging from 14 to 57 years. About one in three psychiatric patients had life time suicidal ideation. Third decade of life was found to be vulnerable for onset of suicidal thoughts.