The copper-free strain-promoted click chemistry between ¹⁸F-labeled aza-dibenzocyclooctyne [¹⁸F]FB-DBCO and various azides is described. [¹⁸F]FB-DBCO was prepared in 85% isolated radiochemical yield (decay-corrected) through acylation of amino aza-dibenzocyclooctyne 1 with N-succinimidyl 4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB). [¹⁸F]FB-DBCO showed promising radiopharmacological profil with fast blood clearance as assessed with dynamic small animal PET studies. Metabolic stability of [¹⁸F]FB-DBCO was 60% of intact compound after 60 min post injection in normal Balb/C mice and blood clearance half-life was determined to be 53 s based on the time-activity-curve (TAC). Copper-free click chemistry was performed with various azides at low concentrations (1–2 μM) which differed in their structural complexity in different solvents (methanol, water, phosphate buffer and in bovine serum albumin (BSA) solution). Reaction proceeded best in methanol (>95% yield after 15 min at room temperature), whereas reaction in BSA required longer reaction times of 60 min and 40 °C upon completion.