The study investigated the Effect of Rapid Developmental Writing Strategies on the Performance of Junior Secondary School one Low Written English Achievers after exposure to sentence construction strategies. The primary goal of the study was to enable Junior Secondary School 1, a student with low written English achievement, to quickly produce proper sentences. The study determined the effects of rapid-developmental writing techniques on the performance of Junior Secondary School 1 poor written English Achievers following exposure to sentence building strategies was one of the study's stated goals. The study set only one research question and one hypothesis that are in line with each other. Quasi-experimental design was used as the research design for the study. The population consisted of pupils from four government junior secondary schools spread over three educational zones. Drawings were made using a cluster sampling approach. The schools were selected using a cluster sampling approach, and a sample of 60 students ware purposefully drawn as the study's participants, consisting of experimental and control groups. Tests that included a sentence construction test employing English Entry Examination design made up the instrument used to produce data. The instrument was verified by the experts from the department of Language Education, curriculum and statistics department Ahmadu Bello University, Zaria. The instrument's validity and contentiousness were confirmed. An assessment of test-retest reliability was analyzed by using the independent sample t-test at 0.05 at level of significant. The study proved that there were significant effects on the performance of Junior Secondary School Students (1) in low written English Achievers exposed to sentence construction. The study recommended that there is need to actually teach low written English Achievers how to write sentences and get a range of experience writing variety of tasks so that they can see how writing varies depending on task.