This book provides detailed instructions on how to perform basic fisheries stock assessment analyses in the R environment. The analyses covered are typical analyses for many working fisheries scientists and, thus, also occur in most upper-level undergraduate and graduate level fisheries science, analysis, or management courses. The book will begin with several foundational chapters that will help the reader become familiar with R within the context of basic fisheries analyses and lots. The remaining chapters build upon the foundational skills with analytical techniques specific to fisheries stock assessments.