This open access book constitutes the proceedings of the LISA 2025 Challenge, held in conjunction with MICCAI 2025 in Daejeon, South Korea, during September 27, 2025. The LISA Challenge serves as a benchmarking platform for developing evaluating automatic image analysis and machine learning algorithms. The 11 full papers included in the book were carefully reviewed and selected from 14 final submissions.The papers are organized in topical sections as follows: Task 1 - Automatic Ultra-Low Field MR Image Quality Assessment; Task 2b - Automatic Basal Ganglia Segmentation from Ultra-Low Field MRI; Tasks 2a and 2b - Automatic Hippocampal and Basal Ganglia Segmentation form Ultra-Low Field MRI; and Tasks 1, 2a and 2b Combined.