The buildings were completed in good time for the school to open at the beginning of the school year in 1911. Due to the strong demand for places, work was also immediately undertaken to build the extra eight classrooms which had always been anticipated and these were ready for the commencement of the 1912 school year. By then, the physical form of the school was much as it was to remain for many decades. The first Principal of the school, FG Brown, helped the school off to an excellent start and was succeeded in 1912 by Joseph Parsons who led the school until 1939. 226 students were enrolled at Perth Modern School on 1 February 1911 and by February the following year, this number had increased to 263. At this time, the school was only nominally co-educational with boys and girls in separate classes and even having separate entrances.
A student’s first two years at Perth Modern School were designed to give a thorough grounding in ‘ordinary secondary school subjects’. For the final two years of their secondary schooling, students had the choice of five streams, namely Arts, Science, Education, Commerce and Agriculture. Extra-curricular activities for students at this time included Cadets, gymnastics and sport. In 1915, Parsons divided the school into Red, Blue, Gold and Sphinx ‘Factions’ and promoted sporting rivalry between them which helped to overcome the problem of the school being excluded by the WA private schools from joining their interschool sporting competition. Discipline at the school was based on self responsibility and students were required to learn the school rules and to respond to them without prompting.
