NETSCOUT SYSTEMS INC — Director's Dealing 2012

May 3, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: NETSCOUT SYSTEMS INC (NTCT)
CIK: 0001078075
Period of Report: 2011-12-31

Reporting Person: SOMMERS DAVID P (Executive Vice-Chairman)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-12-31	Common Stock	J	1622	—	Disposed	185794	Direct
2012-05-01	Common Stock	M	2000	—	Acquired	187794	Direct
2012-05-01	Common Stock	F	634	$18.22	Disposed	187160	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-01	Restricted Stock Unit	$	M	2000	Disposed		Common Stock (2000)	Direct

Footnotes

F1: This transfer was made without consideration by a trust in which the reporting person previously had a pecuniary interest to the beneficiaries of such trust in which the reporting person has no pecuniary interest.

F2: Price is N/A. The shares of Common Stock were transferred without consideration.

F3: 878 of these shares are held by a trust in which the reporting person has a pecuniary interest.

F4: The shares of Common Stock were acquired upon the vesting of certain Restricted Stock Units previously granted to the reporting person.

F5: Price is N/A.

F6: The shares of Common Stock were withheld by the Company to satisfy the reporting person's tax withholding obligation upon the vesting of restricted stock units. The withheld shares were returned to treasury.

F7: Represents the closing price of the Company's Common Stock on April 24, 2012.

F8: Date is N/A.