By the late 1950s, much of the land in Manhasset Hills had been developed by developers.<ref name=":2">Template:Cite news</ref> One of the last major developments to be built was the Cherrywood Homes development, which was built on a 24-acre tract by Barney and Martin Spiegel. The development was built with 88 split-level houses designed by A.H. Salkowitz, and was constructed on one of the last remaining major undeveloped tracts of land available in Manhasset Hills.<ref name=":2" />
In the 1980s and 1990s, roughly 1,000 Manhasset Hills residents attempted to prevent the State of New York from placing a group home in their neighborhood for people with mental disabilities.<ref>Template:Cite news</ref><ref>Template:Cite news</ref><ref name=":0">Template:Cite news</ref><ref name=":1">Template:Cite news</ref> Many were concerned that their property values would decrease because of the group home's presence, and attempted to change a law in order to prevent the home from being established. The residents were successful in preventing the group home from being established in their community, and the home was instead established in nearby New Hyde Park.<ref name=":0" /><ref name=":1" />
Manhasset Hills is a bedroom community of the City of New York and, as such, a significant number of Manhasset Hills residents commute to/from New York for work.<ref name=":9" /><ref>Template:Cite web</ref>
The hamlet itself is predominantly residential in character, with the heavy majority of lots within the village being zoned for single-family homes.<ref name=":12">Template:Cite web</ref> The only area of Manhasset Hills zoned for commercial or industrial uses is located at the extreme southwest corner of the hamlet.<ref name=":12" />
There were 1,224 households, out of which 37.2% had children under the age of 18 living with them, 81.2% were married couples living together, 4.2% had a female householder with no husband present, and 12.7% were non-families. 10.5% of all households were made up of individuals, and 7.4% had someone living alone who was 65 years of age or older. The average household size was 2.99 and the average family size was 3.22.
In the CDP, the population was spread out, with 24.2% under the age of 18, 6.0% from 18 to 24, 20.3% from 25 to 44, 29.0% from 45 to 64, and 20.4% who were 65 years of age or older. The median age was 45 years. For every 100 females, there were 92.0 males. For every 100 females age 18 and over, there were 89.1 males.
The median income for a household in the CDP was $103,540, and the median income for a family was $109,613. Males had a median income of $78,223 versus $48,542 for females. The per capita income for the CDP was $45,009. About 2.3% of families and 2.8% of the population were below the poverty line, including 4.5% of those under age 18 and 3.9% of those age 65 or over.
The Town of North Hempstead owns and maintains two parks within the hamlet:<ref name=":10">Template:Cite web</ref><ref name=":15">Template:Cite web</ref>
As Manhasset Hills is an unincorporated part of the Town of North Hempstead, it is directly governed by the town's government in Manhasset.<ref name=":12" /><ref name=":3">Template:Cite web</ref>
Manhasset Hills is primarily located within the boundaries of (and is thus served by) the Herricks Union Free School District, although the westernmost portion of the hamlet is located within the boundaries of the Great Neck Union Free School District.<ref name=":12" /> As such, children who reside within Manhasset Hills and attend public schools go to school in one of these two districts depending on where they reside within the hamlet.<ref name=":12" />
Manhasset Hills is located within the boundaries of (and is thus served by) the Great Neck Library District and the Shelter Rock Library District.<ref name=":12" /> The boundaries of these two districts within the hamlet roughly correspond to the school district boundaries.<ref name=":12" />
A small portion of the Northern State Parkway traverses the northeastern corner of the hamlet; the historic Long Island Motor Parkway used to pass through Manhasset Hills, as well.<ref name=":4" /><ref name=":6" /><ref name=":7" /><ref name=":8" /><ref name=":12" /> The southwestern corner of the hamlet touches Union Turnpike, and the southwestern tip of the hamlet is at Hillside Avenue.<ref name=":12" />
PSEG Long Island provides power to all homes and businesses within Manhasset Hills.<ref name=":38" />
The former Long Island Motor Parkway's right-of-way now serves as the route of a power line through the area.<ref name=":7" /><ref>Template:Cite news</ref>
Manhasset Hills is located within the boundaries of the Garden City Park Water District and the Manhasset–Lakeville Water District. The boundaries of these two districts within the hamlet roughly correspond to the school district boundaries.<ref name=":12" />
