Science education in Rwandan schools still faces a number of challenges including the lack or shortage of equipment available for science experiments. This paper describes research conducted to assess the impact of using improvised versus conventional laboratory equipment in experiments. Eighty-five lower secondary school students were assessed using a semi-experimental post-test design on thermal expansion of bodies. Data analysis using a t-test produced a t-Stat of 2.74 over a t-Critical of 1.98 indicating a statistical significance between the two experimental groups in favour of the group using improvised equipment. As a result, it is recommended that improvised equipment be used in those instances in which there is a lack or shortage of conventional equipment since students’ achievement was similar regardless of the type of equipment used.