Fingerprint Indexing for Paramodulation and Rewriting (Extended Version) Stephan Schulz Indexing is critical for the performance of automated first-order theorem provers. We introduce \emph{fingerprint indexing}, a non-perfect indexing technique that is based on short, constant length vectors of samples of term positions (``fingerprints'') organized in a trie. Fingerprint indexing supports both matching and unification as retrieval relations. The algorithms are simple, the indices are small, and performance is very good in practice. We have implemented fingerprint indexing in the equational theorem prover E, where it is used for backwards rewriting and superposition. We demonstrate the performance of the index both in relative and absolute terms using large-scale profiling.