This study was conducted to determine the significant relationship between the extent of multitasking practices of teachers and their performance efficacy in Matanao II District, Davao del Sur. This study made use of simple random sampling procedure considering the enormous number of teachers in the research locale. The respondents in this study were determined using the Slovin’s formula. The number of the respondents were 133 out of 220 teachers in Matanao II distributed in the following schools. The teacher respondents answered the checklist based on the indicators in the researcher made questionnaires describing multitasking practices of teachers and their performance efficacy. The statistical tools used were Mean, Pearson r, and Regression. The findings revealed that the extent of multitasking of teachers in terms of lesson planning is Very Large Extent, the extent of multitasking of teachers in terms of classroom instruction is Very Large Extent, the extent of multitasking of teachers in terms of Development of Instructional Materials is Large Extent, the extent of multitasking of teachers in terms of Development of Educational Innovation is Very Large Extent, and the extent of performance efficacy of teachers in terms of accuracy of Work is High, the extent of performance efficacy of teachers in terms of work efficiency is High, the extent of performance efficacy of teachers in terms of timeliness is High, there is a significant relationship between extent of multi-tasking of teachers and the performance efficacy of teachers. Likewise, the domains of multitasking practices of teachers which influence the performance efficacy, it can be seen from the table that the overall tabulated p-value is 0.002 which is lower than 0.05 level of significance which means that all domains of multi-tasking practices of teachers influenced the performance efficacy.