Kenya models her teacher education on western countries' education systems. More recently, non-western industrialized countries have started to collaborate with Kenya on science education. From July 1998 to June 2003, the Government of Kenya with assistance from the Government of Japan, through Japan International Cooperation Agency, started to strengthen the teaching of secondary school chemistry through a cascade teacher education pilot project. In collaboration with the education officials, principals associations, and parents associations in the pilot districts, the project was planned, implemented, administered, monitored and evaluated from the headquarters in Nairobi. In this multi-site qualitative research case study, I examined multi-site cases of teachers practices and experiences about the chemistry unit lesson planning and implementation following the in-service teacher education program in Kenya. In this study, a descriptive comparison was made of chemistry district educators in the Strengthening of Mathematics and Science in Secondary Education (SMASSE) Project in-service program in four different school settings (boys boarding, girls boarding, mixed boarding, and mixed day). The intent of this study was to determine what changes, if any, teachers made in the design and implementation of their lessons, how these changes were implemented, and why the teachers made such changes. The participants used a new lesson plan format. They planned, prepared and implemented student-centered activity lessons. They greatly improved their teaching skills and were able to improvise teaching/learning equipment during their chemistry unit lessons on the Periodic Table, mole concept, electrochemistry, and organic chemistry.