This research focused on the relationship between teachers' self-efficacy application package and classroom practices in senior secondary school in Zaria zone, Kaduna state. Four objectives with corresponding research questions and hypotheses were formulated to guide the study. Survey research design was employed. The study revived related literature on teachers self-efficacy application packages and how it been used in classroom practice. The population of the study consist of 293 male and 203 female (494) senior secondary schools teachers' in Zaria zone. A sample size of 214 teachers were randomly sampled using Kreejie and Morgan sampling procedure. Questionnaire on teachers' self-efficacy application packages and classroom practices was used for data collection, it was validated by four experts from three Departments in ABU, Zaria. Thereafter, instrument was pilot tested at Government Girls Day Senior Secondary School Samaru Zaria, a reliability coefficient of .956 on teachers' self-efficacy application package was established, while Cronbatch Alpha of classroom practices is .968. Questionnaire was administered and data collected thereafter were analyzed using descriptive statistics of frequency and simple percentage for analyzing demographic data, while mean and standard deviation were used to answer the research questions. Hypotheses were tested using Spearman rank-order. The findings revealed that there is a positive relationship between teachers' computer application package self-efficacy in Microsoft Word, Microsoft Excel, PowerPoint, and Internet in classroom practices. Moreover, the research found that those teachers with high levels of self-efficacy application package do not necessarily use it. Therefore, there is a positive relationship between teachers' self-efficacy application package on the three variables and classroom practices. Based on these findings it is recommended that teachers should be given in-service professional development training on the use of computer application package to improve their classroom practices