Background: Psychological distress (PD) has a major impact on quality of life. We studied the incidence of PD before and after radiotherapy for painful bone metastases. Furthermore, we aimed to identify factors predictive for PD. Methods: Between 1996 and 1998, the Dutch Bone Metastasis Study included 1157 patients with painful bone metastases. Patients were randomized between two fractionation schedules. The study showed a pain response of 74% in both groups. Patients filled out weekly questionnaires for 13 weeks, then monthly for two years. The questionnaires included a subscale for PD on the Rotterdam Symptom Checklist. We used generalized estimating equations and multivariable logistic regression analyses. Results: At baseline, 290 patients (27%) had a high level of PD. For the entire group, the level of PD remained constant over time. The majority of patients with a low level of PD at baseline remained at a low level during follow-up. In patients with a high level of PD at baseline, the mean level of PD decreased after treatment and stabilized around the cutoff level. Female patients, higher age, worse performance, lower pain score and worse self-reported QoL were associated with an increased chance of PD, although the model showed moderate discriminative power. Conclusions: A substantial proportion of patients had a high level of PD before and after radiotherapy for painful bone metastases. Most patients who reported high levels of PD when referred for palliative radiotherapy remained at high levels thereafter. Therefore, screening of PD prior to treatment seems appropriate, in order to select patients requiring intervention.