You need to do things at several places
1) Declare your charset in your HTML page's header.
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
2) You should send a [man]header[/man] that indicates your page is UTF-8:
header('Content-Type: text/html; charset=utf-8');
3) Your database tables need to be encoded as utf-8
4) You need your php page to connect using charset utf8:
if (!$mysqli->set_charset("utf8")) {
printf("Error loading character set utf8: %s\n", $mysqli->error);
} else {
printf("Current character set: %s\n", $mysqli->character_set_name());
}
5) You should be using the [man]mbstring[/man] functions to parse your strings.
There could be more. This page looks really helpful.