Objectives: This study aims to analyse potential relationships between European Alliance of Associations for Rheumatology (EULAR)/American College for Rheumatology (ACR) classification criteria domains and individual criteria items in a large systemic lupus erythematosus (SLE) patient cohort. Previous findings showed meaningful associations only within organ systems, but not across them. We seek to validate these findings and expand on them. Methods: Cluster analysis was performed on the EULAR/ACR criteria domains in a cohort of 1196 patients with SLE. Criteria items were analysed as binary variables (ever present = 1, always absent = 0) and tested for associations using network analysis. Results: The cluster analysis resulted in 10 clusters, but with no convincing patterns beyond antibody-organ relationships. Relevant correlations between items were found within the domains, but some associations between items of different domains still showed significant, if mostly weak associations with r values of 0.10 to 0.26. These included correlations between antibodies to double-stranded DNA and Sm, low complements and lupus nephritis, and between antiphospholipid antibodies and thrombocytopenia. Anti-Sm antibodies were also associated with alopecia and leukopenia, autoimmune haemolysis with seizures, and serositis with fever. Joint involvement was negatively correlated with lupus nephritis and thrombocytopenia. The network analysis showed fever and serositis detached from the other items, with items within organ domains grouped. Conclusions: This comprehensive analysis of relationships between the domains and items of the EULAR/ACR SLE classification criteria underlines the relevance of the domain structure. Overall, the data are more compatible with chance distribution than with fixed subsets of SLE.