TECHNISSIS' clients come from many economy's branches, such as: Technical companies -Civil Engineering, Industry (Industrial production processes- packaging), Industrial fabrics (sunshades, tarpaulins), Galvanizing Plants, Car repairs, Insulation, Fish farming, Plastic floors, Swimming Pools, Maintenance of artifacts, Electronics, Industry of: chemicals, food, wood, furniture, Power plants, Biological Treatment, Waste to energy plants, Semi conductor, Potable water treatment, Desalination plants, etc.

For example we can mention the following:

• AEGEK CONSTRUCTION SA
• AKTOR CONSTRUCTIONS
• ALPHA COPY LTD
• ALTO SA (CONSTRUCTION MATERIALS)
• ANDROMEDA SA
• BIC SA
• CARTA SA
• COCA COLA HELLENIC BOTTLING COMPANY SA
• COLGATE-PALMOLIVE HELLAS SA
• CONSORTIUM AEGEK-AKTOR-SELI-J&P-AVAX
• CONSORTIUM AKTOR-THEMELIODOMI-PANTECHNIKI-EFKLIDIS
• CONSORTIUM KORONIS - UKPS LDT - ENVITEC
• DOMISSIMA SA
• DROMEAS SA
• ELAIS - UNILEVER HELLAS SA
• ELFON LTD
• ELVAL SA
• ERGOTECH SA
• EUROPA PROFIL ALUMINUM SA
• EUROPLAST SA
• FAGE SA
• GALAXIDI MARINE FARM SA
• HELLENIC FISHFARMING SA
• INTERFISH AQUACULTURE SA
• J & P AVAX SA
• J & P ENERGY & INDUSTRIAL
• JOHNSON & JOHNSON HELLAS SA
• KAPLANOGLOU SA
• KLIDARAS FAMILY SA
• NIREUS FISHFARMING SA
• OMNITEK SA
• PAPASTRATOS (PHILIP MORRIS)
• PETZETAKIS SA
• PHILIPS HELLAS SA
• PISCINA AZUL (LOGOTHETIS B.A. SA)
• PISCINES IDEALES
• PLASTIKA FEROR SA
• PLASTIKA KRITIS SA
• PROCTER & GAMBLE HELLAS
• SAO SA
• SEALED AIR HELLAS SA
• SELONDA FISHFARMING SA
• SHELMAN SA
• SIKA HELLAS SA
• VALPAK SA
• VIVARTIA SA
• YIOULA SA