Try to figure things out yourself first.
Searching the mysql manual would be a good idea.
Still, one way to do it would be:
SELECT columns FROM tablename ORDER BY table_id DESC LIMIT 1
where columns would be the fields required from table tablename.
table_id would be the primary key, probably INT NOT NULL AUTO_INCREMENT
DESC means we order in descending order, and LIMIT 1 means we only take the 1st record in this order, i.e. the last record.
Another way might use [man]mysql_insert_id/man, but that's another matter.