1957年前，喇沙書院響喇沙小學現址開辦第七、八班，即分別依家嘅小學五、六年級。1957年9月，正式脫離喇沙書院成立喇沙小學，五、六年級各兩班，由彭亨利修士擔任創校校長，在任達27年。當時嘅校舍喺喇沙書院嘅附屬建築。下午上課，上午比左教育署借用。
Before 1957, La Salle College opened classes 7 and 8 at the current site of La Salle Primary School, which are now Primary 5 and 6 respectively. In September 1957, La Salle Primary School was officially separated from La Salle College to establish La Salle Primary School, with two classes in grades 5 and 6, with Brother Pa Henry as the founding principal, a position he held for 27 years. At that time, the school building was in the annex building of La Salle College. Classes were held in the afternoon, and in the morning they were borrowed by the Education Department.