Si, eso es correcto. Funciona bien aquí:
CREATE TABLE table1 (id int, username nvarchar(30));
CREATE TABLE table2 (id int);
CREATE TABLE table3 (id int);
CREATE TABLE table4 (id int);
INSERT INTO table1 VALUES (1, 'Foo'),(2, 'Bar');
INSERT INTO table2 VALUES (1),(2);
INSERT INTO table3 VALUES (1),(2);
INSERT INTO table4 VALUES (1),(2);
SELECT COUNT(*) FROM table1;
2
SELECT COUNT(*) FROM table2;
2
SELECT COUNT(*) FROM table3;
2
SELECT COUNT(*) FROM table4;
2
DELETE t1, t2, t3, t4 FROM
table1 as t1
INNER JOIN table2 as t2 on t1.id = t2.id
INNER JOIN table3 as t3 on t1.id=t3.id
INNER JOIN table4 as t4 on t1.id=t4.id
WHERE t1.username='Foo' AND t1.id='1';
SELECT COUNT(*) FROM table1;
1
SELECT COUNT(*) FROM table2;
1
SELECT COUNT(*) FROM table3;
1
SELECT COUNT(*) FROM table4;
1
Si no te funciona, tal vez puedas modificar este ejemplo para mostrar el problema que tienes.