Microbiological contamination remains one of the most critical quality risks in pharmaceutical manufacturing, particularly in sterile and non-sterile dosage forms. Such contamination can lead to product recalls, regulatory actions, and serious threats to patient safety. Corrective and Preventive Action (CAPA) systems form a fundamental component of pharmaceutical quality systems and play a vital role in identifying, investigating, and mitigating microbiological contamination events. This review provides a comprehensive overview of microbiological contamination sources in pharmaceutical production and examines CAPA strategies driven by microbial deviations. Regulatory expectations from agencies such as the US FDA, EU-GMP (Annex 1), WHO, and ICH guidelines are critically discussed. The review highlights common root causes of contamination, tools used for root cause analysis, and effective corrective and preventive measures implemented across manufacturing environments. Additionally, challenges in CAPA implementation, frequent deficiencies cited in regulatory inspections, and emerging trends such as rapid microbiological methods and data-driven contamination control strategies are explored. The review emphasizes the importance of a proactive, risk-based CAPA approach integrated with contamination control strategies to ensure sustained microbiological compliance and product quality.