This book constitutes the refereed proceedings of the Second EAI International Conference on Pervasive Knowledge and Collective Intelligence on Web and Social Media, PerSOM 2023, which took place in Hyderabad, India, during November 24-25, 2023.The 28 full papers included in the proceedings were carefully reviewed and selected from 70 submissions. They focus on information and Web mining, social network analysis, semantic network analysis, trust, reputation, social control and privacy, information reliability, and Web and content authenticity.