MOTIVATION: Amplicon-based nanopore sequencing is increasingly used for molecular surveillance during epidemics (e.g. ZIKA, EBOLA) or pandemics (e.g. SARS-CoV-2). However, there is still a lack of versatile and easy-to-use tools that allow users with minimal bioinformatics skills to perform the main steps of downstream analysis, from quality testing to SNPs effect to phylogenetic analysis. RESULTS: Here, we present ONTdeCIPHER, an amplicon-based Oxford Nanopore Technology sequencing pipeline to analyze the genetic diversity of SARS-CoV-2 and other pathogens. Our pipeline integrates 13 bioinformatics tools. With a single command line and a simple configuration file, users can pre-process their data and obtain the sequencing statistics, reconstruct the consensus genome, identify variants and their effects for each viral isolate, infer lineage and, finally perform multi-sequence alignments and phylogenetic analyses. AVAILABILITY AND IMPLEMENTATION: ONTdeCIPHER is available at https://github.com/emiracherif/ONTdeCIPHER. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.