$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow"); $a2=array("e"=>"red","f"=>"black","g"=>"purple"); $a3=array("a"=>"red1","b"=>"red","h"=>"yellow"); $result=array_intersect($a1,$a2,$a3); // Output // Array ( [a] => red )