The aim of the paper is to explore the knowledge base of high school physical science teachers, from selected high schools in Lesotho, regarding the integration of information and communication technologies (ICTs) into the curriculum. The new physical science curriculum in Lesotho requires the use of ICTs for teaching. The teachers' use of ICTs was explored through a questionnaire based on the technological pedagogical content knowledge model (TPACK). Data were analysed using the statistical analysis software (SAS) and the results showed that 77% of the teachers used ICTs for teaching, while 80% used them for non-teaching activities. The mean score for teachers' TPACK was 2.88. This score is below the average of three for the Likert points of the items on teachers' TPACK, which was set as the acceptable level for this paper. Therefore, the study concludes that Lesotho teachers do use ICTs for teaching physical science even though their TPACK may be below average. Their low TPACK may be an indication that they used ICTs to get more information about the content, rather than for delivering the lessons. There is thus an urgent need to increase the support for teachers to maximise the use of ICTs for teaching.