Since its inception the Ainslie Tennis Club has had problems attracting a large active membership. However, a common feature of the club has been a strong group of loyal members and a further group of transient members who use the club facilities but tend not to become involved in administration or social events.

Initially it was decided to confine membership to an area called "The Weatherboard" part of Ainslie. However, it was quickly realised that the club could not survive by restricting membership.

The second world war had a major impact on club membership. However, the post-war period saw the club in a strong position with an average of 105 members between 1945 and 1949. The 1950's were also strong years for the club. Between 1953 and 1959 the club had a continuous membership of over 100 with a peak membership of 160 in 1957. However, in those years there was concern over the lack of members between the ages of 20 and 30.

From the 1960's till the early 2000's there were problems in attracting members. Letter-drops, advertisements and open days were used to stimulate interest, but they generally met with limited success. 

However, by the early 2010's the Club's membership had grown to over a 100 members and and peaked in 2017 when 130 members joined. The introduction of Book A Court in 2017 provided an easy, alternative way for non-members to access the courts at a reasonable price and numbers began to decline again with numbers closer to 100. 

The COVID-19 pandemic in early 2020 initially closed the courts to everyone and then re-opened for members only. As a result membership numbers surged during the traditional quiet period of the cold, middle months and 2020.  By 2021  the club's membership increased to 150 and then once sporting options once again widened with the lessening of COVID, numbers started to drop off.  This was further exacerbated by the introduction of rolling memberships meaning that you join for 12 months from the date of application as opposed to the previous system of prorata memberships when you initially jopined and then membership from 1 Jan till 31 Dec. The new approcah encourages mambership but also facilitates non-renewals.