Seks said that 2005 would be remembered as a year in which Croatia had achieved "valuable and far-reaching successes of vital importance for the future of all its citizens."
"The international community has recognised Croatia as a reliable partner, a guarantor of peace and security, a promoter of democratic values, a proponent of reform and as a country with an appropriate level of economic recovery and valuable economic potential.
"At a time when Croatia is safely marching to full membership of the European community of nations, for our own sake and for the sake of our credibility we must continue to focus our attention on ensuring unconditional respect for the rule of law in all areas of life in our society," the Parliament Speaker wrote in his message.
In a separate message, Seks extended his best wishes to the Jewish community in Croatia for Hanukkah, the festival of light which this year is celebrated on 26 December.
"Let the light, as a symbol of hope and regeneration, give us all the strength to build together a world of co-existence, peace, understanding and mutual respect," Seks said.