Diffuse large B-cell lymphoma is a common non-Hodgkin lymphoma and covers about one third of global non-Hodgkin lymphoma cases each year. The lymphoma is characterised by B-cells with large nuclei which makes the cells unable to function normally as a part of the immune response. MicroRNAs, which are small noncoding RNA, can be used as biomarkers for the diagnosis, prognosis and treatment in many different diseases. However, the pathways regulated by microRNAs in connection to diffuse large B-cell lymphoma are not well understood. The aim of this study was to find hub microRNAs and their pathways in diffuse large B-cell lymphoma. This was done by identifying differentially expressed microRNAs, finding their target genes and building networks of the microRNAs and their targets. Gene ontology terms and KEGG pathways were identified for each network. This study found three microRNA hubs hsa-let-7f-1-3p, hsa-miR-200c-3p, and hsa-miR-507. Each of them has been shown to regulate tumours in other cancer types though they have not been connected to diffuse large B-cell lymphoma before. The target genes have also been found to play central roles in general tumour formation. This study found that known tumour suppressor genes were down-regulated while genes that aided in tumour formation were up-regulated. The gene ontology analysis showed that many of the target genes take part in the normal development of the human body, but the KEGG pathways were concentrated around cancer formation. The microRNAs show promise as prognostic markers and targets for developing treatments.