The MoEST (2006) initiated the integration of multimedia into teaching of Kiswahili grammar aspects so as to enhance the following language aspects: pronunciations, spellings, punctuations, constructing sentences correctly and general appropriate use of Kiswahili language patterns. Though, this has not been achieved as witnessed by students’ low performance on Kiswahili grammar aspects CATs over years among Sub-County secondary schools in Nakuru County, Kenya The objective of the Paper was to determine the differences between students taught Kiswahili grammar aspects using multimedia and those students taught the same content using TTMs on learning achievements on Kiswahili grammar aspects. This Paper employed a causal-comparative design. A sample of 750 participants was drawn from a target population of 12900 subjects. Stratified, purposive and simple random sampling methods were used to select the study sample. Questionnaires and Document Analysis Guide were used to collect quantitative and qualitative data. Piloting was done in three schools to determine the validity and reliability of the research items in two weeks before the commencement of the actual study, whereby the study confirmed that the instruments were valid and reliable; the students’ each was computed separately using Cronbach’s Alpha Formula internal consistency and students’ alpha coefficient yielded an alpha of 0.75 which were considered adequate for the study. Mean and standard deviations were used to analyze quantitative data while independent T-tests were used to test the hypothesis so as to find out the differences between the two means on performance on Kiswahili reading comprehension between the two groups. Quantitative data was presented and interpreted in frequency table distributions, bar graphs and pie-charts. The findings of the study established that multimedia enhances learning achievements on Kiswahili grammar aspects. The t-test findings also indicated that there was a statistical significant difference in favour of the multimedia group students it was concluded that the use of multimedia in teaching Kiswahili grammar aspects increases learning achievements on Kiswahili grammar aspects.