1. Details of the person discharging managerial responsibilities / person closely associated

a) Names

Gary Elden & Alex Smith

2. Reason for the notification

a) Position/status

CEO & CFO

b) Initial notification /Amendment

Initial notification

3. Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor

a) Name

SThree plc

b) LEI

2138003NEBX5VRP3EX50

4. Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transactions have been conducted

a) Description of the financial instrument, type of instrument

Identification code

Ordinary shares of 1p

GB00B0KM9T71

b) Nature of the transaction

Purchase of Partnership and Matching shares under the Share Incentive Plan ("SIP")

c) Price(s) and volume(s)

Purchase of Partnership and Matching shares under the Share Incentive Plan ("SIP")

Names

Gary Elden

Alex Smith

Price(s)

333.0p

333.0p

Volume(s)

57

57

d) Aggregated information

- Aggregated volume

- Price

N/A

e) Date of the transaction

14/05/2018

f) Place of the transaction

London Stock Exchange