Worldwide, the elderly are at a greater risk of suicide than other age groups. There is a paucity of research exploring risk factors for suicide in hospitalized elderly patients. Therefore, a study designed to explore the prevalence and characteristic of suicidal ideation (SI), such as QOL (quality of life), a wish to die (WTD), and other factors in elderly inpatients with medical or surgical conditions in Taiwan was warranted. A total of 2199 hospitalized elderly patients over age 65 were enrolled. Demographic data, 5-item Brief Symptom Rating Scale (BSRS-5), and the World Health Organization Quality of Life-BREF (WHOQOL-BREF) data were collected. Logistic regression models were used to find the SI-related factors for all participants and to investigate the covariates correlated with WTD in patients with SI. Receiver operating characteristic (ROC) curve analysis was used to find the most important items of the BSRS-5 predictive of SI in this population. SI was found in 3.1% (68/2199) of the elderly. The statistically significantly factors associated with SI were: BSRS-5 item 2 (depression) (odds ratio [OR] = 2.15, 95% confidence interval [CI] = 1.56–2.98), item 4 (inferiority) (OR = 1.62, 1.23–2.13), item 5 (insomnia) (OR = 1.52, 1.13–2.05), and physical domain of WHOQOL (OR = 0.84, 0.72–0.99). QOL15 (mobility) (OR = 0.64, 0.46–0.90) and QOL 16 (satisfaction with sleep) (OR = 0.62, 0.44–0.88) were also significantly associated with SI. The status of living alone (OR = 4.44, 1.24–15.87), QOL 26 (absence of negative feeling) (OR = 0.38, 0.15–0.98), and QOL 27 (being respected/accepted) (OR = 0.43, 0.20–0.92) were significantly associated with WTD among inpatients with SI. The ROC curve analysis revealed that depression, inferiority, and insomnia were the most important items in the BSRS-5 significantly associated with SI among the elderly inpatients. To provide physical recovery and maintain mental health for physically ill elderly inpatients, setting up a multi-faceted approach targeting the aforementioned determinants of SI and WTD for reducing the risk of suicide attempt, and exploring other factors correlated with suicidal behaviors, are important topics and directions for clinical practice and further research.