[7] In 1949 the main part of the school grounds was purchased by the NSW Government for the purpose of agricultural education.

At that time the school consisted of a wooden, five-room classroom block, a small staff-room and ablution facilities.

For his efforts, Hoskin was awarded the Queen's Silver Jubilee Medal in 1977 and the Order of Australia for Services to Education in 1990.

The first group of students to complete the full five years of secondary education at the new high school sat for the Leaving Certificate in 1961.

James Ruse AHS was originally a boys only school, but gradually became co-educational after an initial intake of 24 female students into Year 11 in 1977.

Since the mid-1990s, James Ruse has undergone an extensive building works program funded by both parents of students and the State and Federal Governments.

James Ruse Agricultural High School has ranked 1st in the national government NAPLAN tests across Australia every year since their establishment.

[16] [17] James Ruse Agricultural High School can be noted for its strong participation in extracurricular and competitive activities,[18] as listed below.

The school participates in volunteering and fundraising activities, including World's Greatest Shave and the 40 Hour Famine, and has links with Interact and Amnesty International.

[21] The Australian Army Cadets (AAC) operates a school-based unit at James Ruse for students of the school.

With a current strength of over 300,[24] representing over a third of the students in the school, JRAHSACU is one of the largest cadet units in Australia.

The unit conducts a weekend bivouacs three times a year which involve hiking interspersed with lessons on topics such as fieldcraft, radio telecommunications and first aid.

Each year, the unit conducts its week-long Annual Adventurous Activity at a location within Australia or occasionally New Zealand.

The unit is a part of the NSW 2nd AAC Brigade, and consists of four companies (Alpha, Bravo, Charlie, and Delta).

In 2022, JRAHSACU was featured as the Guard of Honour at the Sydney Hyde Park War Memorial in the online ANZAC service video, made in lieu of the COVID-19 pandemic, which was released to units and communities around New South Wales.

In 2023, JRAHSACU was featured as the Guard of Honour at the NSW Department of Education's ANZAC Day Service, and was selected as part of the Royal Guard of Honour for the first occurrence in seventy years of the King's Birthday Parade for the Governor of New South Wales at Government House, Sydney.

Through the SRC, students have some representation on the school steering committees (along with parents and staff), and also play a minor role in decision-making processes relating to curriculum, building plans, and resource allocation.

However, following the introduction of a new HSC curriculum by the Board of Studies in 2001, the school made Year 11 optional (with the decision supported by a survey among students).

[34] Agriculture is a significant part of the school's curriculum, with students undergoing study of the subject both on and off-site, where students study and visit agricultural enterprises both in the Greater Sydney region, with visits to regional horticultural farming enterprises such as the Sydney Royal Easter Show and farms in Bathurst and in Gloucester.

[35][36] The school leases approximately ten hectares of land from the neighbouring electricity sub-station for use in practical agriculture lessons.

The farm is arranged to include a vegetable garden, a classroom, a glasshouse and nursery, a greenhouse, an orchard, experimental plots, an area for field crops and a livestock section, among others.

In addition to its use for educational purposes, the farm also supplies a wide variety of agricultural produce including: Cattle – Angus stud, paraded annually at the Castle Hill Show by the Cattle Group, and sold at Camden Sales yard; Sheep – First-cross Ewes & Prime Lambs; Eggs – Free-range eggs; Poultry Meat – Broilers raised and sold onsite, Oranges – Washington Navel; Peaches – Flordagold and Sherman's Red varieties; Sweet Corn – Shimmer variety; James Ruse Gold Rose – A privately crossbred rose variety the rights were donated to the school in 1999 in celebration of its 40 years of teaching; Apiary – Honey sold on-site in jars; and Macadamia Nuts.

Barrengarry House, the school's main administration block, is located near the southwest entrance of the school, adjoining the Senior Common Room and the Library and housing the offices of the principal, deputy principals, head teacher of administration and the administration staff on the lower floor, and the counsellor's office, uniform shop and function rooms on the upper floor.

It was originally the home and property of the Felton family, and was built in 1885, with the architect thought to have been Charles Slatyer.

The wing is a two-storey building with a mix of classrooms, workshops and modern computer labs, and overlooks the gymnasium on its northern side.

The Cameron Block (or "C-Block") is a three-storey building with a variety of classrooms, science labs, computer rooms and lockers.

The Powe Block (or "P-Block") is a two-storey building connecting L-Block and C-Block which houses most (but not all) of the school's laboratories.