The 18th annual conference ITAT took place in Hotel Plejsy, Slovakia, from 21 to 25 September 2018. ITAT, meaning Information Technologies - Applications and Theory, is a place where young researchers, doctoral students and their teachers meet every year to present their results from the various fields of computer science. They come mainly from the Czech and Slovak republic, but the conference is open to participants from other countries as well. In addition to the professional program, much time is devoted to informal discussions, and above all to the formation and maintenance of friendly relations between scientists from the both countries. The Slovak mountains make a perfect background for that. The 2018 conference consisted of the main track and 4 workshops: Slovenskocˇ eský NLP workshop (SloNLP) WWW-Challenges and Trends (W3-ChaT) Combinatorics on words (CoW) All the 37 submitted papers were reviewed by two or more independent reviewers. The proceedings contain 26 scientific papers and abstracts of four invited talks: Radim Beˇ lohlávek (Univerzita Palackého v Olomouci): Fuzzy Logic and Mathematics: A Historical Perspective Katarína Cechlárová (Univerzita P.J.Šafárika v Košiciach): Budúci ucˇ itelia do škôl - problém (nielen) matematický Filip Šroubek (AVCˇ R): Digital image restoration: blur as a motion cue Petr Ambrož (Cˇ VUT): Palindromy pohledem kombinatoriky na slovech