In this study three different EFL textbooks designed for pupils in 8th grade in Swedish secondary school were analyzed. The analyzed textbooks are Second Time (1997), Prime Time (2009) and Sparks (2017). By limiting the text selection to only comparing fictional excerpts in the textbooks, two texts from each textbook were randomly selected. These six texts have been used as the primary sources for this analysis. The aim of this study was to investigate how textbooks can contribute to EFL learners and their vocabulary acquisition by determining the lexical diversity and density of the textbooks and look at their frequency in word occurrence. Furthermore, we discuss the implications of textbook selection in relation to these lexical phenomena. The research questions investigated are 1, What is the lexical diversity of each textbook? How many tokens, types and noun lemmas and verb lemmas are found in the texts and the textbooks? 2, What words are considered to be high-frequency words and how do they correspond to everyday English, according to the New General Service List. 3, What is the lexical density of each textbook? Finally, 4. What are the implications in relation to textbook selection? The conclusion regarding the research questions is that the textbook Sparks could arguably be considered the book that corresponds best to the researched criteria because the data showed that Sparks contains a higher amount of lexical diversity and density, together with a higher number of high-frequency words which corresponds to the NGSL. However, this conclusion is drawn solely on the researched criteria regarding vocabulary. To obtain a broader understanding of what textbook to consider, a more qualitative study that involves more criteria, such as themes or grammar would be needed.