Eva, Lewis and Ewan Harvey, 16, of Duncanrig Secondary, East Kilbride, paid tribute to their teachers after the impressive haul.
The pupils' passes, which included the core subjects of English and mathematics, range across the spectrum of arts, humanities and sciences.
Eva is celebrating passes in maths, English, biology, chemistry and geography; Ewan secured his in maths, English, chemistry, physics and religious, moral and philosophical studies; Lewis achieved maths, physics, English, religious, moral and philosophical studies and music.
Ewan said: "If you listen carefully when teachers are explaining the basics, there is less pressure on you to study hard out of school."
George Randall, acting head teacher, said: "Special congratulations must go to the Harvey family for their remarkable achievement.
"We are delighted with the success of all pupils who have recently received their SQA grades.
"Our results were up from last year and I am proud of all our pupils who achieved five As at Higher grade and the 37 who secured five Highers."
The Harvey siblings are now likely to embark on different career paths. Eva wants to study biology, Lewis intends to pursue physics and Ewan wants a career in aeronautical or mechanical engineering.
However, before then, more qualifications are likely to follow, with all three staying on at school.
Eva and Lewis will be taking three Advanced Highers, while Ewan will be studying for two Advanced Highers, as well as two further Highers.