Cobalt modified LTL-type zeolite (K-CoL) was hydrothermally synthesized, partially substituting framework aluminum for cobalt atoms. The isomorphous substitution of cobalt into the zeolite structure was confirmed by XRD, TGA, UV-VIS, XPS and chemical analyses. Cobalt ions were removed together with K+ following NH4Cl exchange, indicating Co2+ also to be present as balancing or occluded cations into the channels of K-CoL. The epoxidation of R-(+)-limonene in the presence of a sacrificial aldehyde over K-CoL yields 70.7% cis-1,2-epoxide. Besides, the activity of reused K-CoL was more stable after three consecutive runs than a Co impregnated sample containing the same amount of cobalt as in K-CoL.