The source parameters of the Lefkada earthquake sequence (14.08.2003, M 6.5) and the Psachna swarm sequence (June-July 2003) were analyzed. Using teleseismic waveform modeling we interpret Lefkada earthquake as a multiple-event consisting of 3 distinct subevents. The source properties of the largest earthquakes of the aftershock sequence were also analyzed, using regional waveform modeling and two prominent types of focal mechanisms were revealed. The events of the Psachna sequence were located and re-located using the HypoDD method. Also focal mechanisms were calculated for all the events of magnitude M>2.7 using both regional waveform modeling and first motion polarities of the P-waves. The seismotectonic role of the area and the connection with adjacent fault systems was investigated.