: Five important world bird lists were analyzed and compared. Since the Boyd et al. and Cornell University world bird counts are identical to Clement's et al. values, the first two are not evaluated here. The analysis of HBW's world bird count has in the highest values, showing 6,648 for Passeres (P) and 4,487 for Nonpasseres (NP), totaling 11,135. The world bird count values according to Gill et. al. totals 10,714 (i.e., P 6,380 and for NP 4,334) whereas Clements's et al. states total of 10,930(for P 6,518 and for NP 4,412). It was also found that in the NP some bird families, (such as Sarothruridae, Bucorvidae and Psittaculidae) are not listed HBW's World Bird List, while they are listed both in Clement's and Gill's World Bird List. The families Cettiidae, Erythrocercidae, and Hyliidae (in P), are given in Gill's World Bird List, but not in Clement's and HBW's. The families Tichodromidae and Icteriidae are not included in HBW's World Bird List, but are included in the others. The family Platylophidae is not included in Gill's World Bird List, but is included in the others. The family Oxyruncidae is included in HBW's World Bird List, but not in the others. The family Sylvidae has been split into two families namely, in Gill's List, Sylvidae and Paradoxornithidae, in Gill’s World Bird List. The family Paradoxornithidae is not listed both in Clement's or and in HBW's. The family Pellorneidae was listed in Gill's World Bird List as two families (i.e.,Pellorneidae and Alcippeidae).