Effective pain management is a cornerstone of quality nursing care, yet knowledge gaps and systemic barriers often hinder optimal practice, particularly in low-resource settings. This study aimed to assess nurses’ knowledge and attitudes regarding pain management, evaluate their self-reported pain practices, and explore the role of perceived organizational support in shaping pain management competence among nurses in a tertiary care hospital in Lahore, Pakistan. A cross-sectional survey was conducted with 120 registered nurses using the Knowledge and Attitudes Survey Regarding Pain (KASRP), a perceived organizational support scale, and a self-reported practice checklist. Descriptive statistics revealed that only 22.5% of nurses demonstrated good knowledge, while 45% had moderate and 32.5% poor knowledge levels. Perceived organizational support was moderate on average, and although self-reported practice scores were relatively high, they did not significantly correlate with knowledge levels. Independent samples t-tests showed no significant differences in knowledge or practice scores by gender. Pearson correlation indicated a significant positive association between organizational support and knowledge scores. Multiple linear regression identified organizational support as the only significant predictor of knowledge scores (p = 0.003). These findings highlight the critical role of organizational factors in fostering clinical competence and suggest the need for system-level interventions—such as regular training, managerial support, and access to protocols—to improve pain management outcomes in nursing practice.