This book constitutes the thoroughly refereed postproceedings of the 16th International Symposium on Logic Based Program Synthesis and Transformation, LOPSTR 2006, held in Venice, Italy, July 2006 in conjunction with ICALP 2006, PPDP 2006, and CSFW 2006. The 14 revised full papers cover tools for program development, partial evaluation and program transformation, security and synthesis, debugging and testing, as well as termination and analysis.