This thesis studies how small Swedish firms used their patents between 1998 to 2016. We also examine the association between used and unused patents and their characteristics such as technological class, family size, inventors, claims, grant and authority. Research data are collected from both databases (PATLINK, Serrano, and PATSTAT) and survey. We found that 79% of patents are used in small Swedish companies and family size is associated with patent use. In small Swedish companies, the increase in patent family size will decrease the frequency of use.