In our modern world where there is an unbelievable amount of advertising, it is really hard to stand out to attract customers. The Advertising industry is going through enormous changes with the escalating use of digital and social media. Traditional advertising is no longer striking, and persuading to customers. In an era of visual overload, communicating visual messages through advertising must to be highly engaging, striking the attention and involving the public emotionally more than ever. Inspiration from art, combined with advertising creative tactics is becoming the base to implement innovative advertising formats that succeed to gain the precious attention of modern customers progressively engaged in dynamic, unique and interactive contexts. Art installations are one of the most powerful and immersive of all art forms. Accordingly, art installations could be one of the most inspirational tools to provoke customers' curiosity through what is known as Installation Advertising; which is a popular type of Ambient Advertising; when a brand disrupts the consumer's natural environment by introducing a foreign object that looks out of place. Installation Advertising is all about surprise; its main goal is to surprise the audience in a positive manner. Surprise is great creative tactic to make an advert stand out, grab the consumers attention, engages them and most importantly gets them talk especially in a context where people are used to repetition and may not be expecting any changes. Probabilities are they'll snap a picture, take a selfie or pose with a friend; following thing the installation advert isn't just on the street or in the mall, it's on social media, maybe going viral, maybe one day ending up on a blog article inspiring the next wave of Installation advertising innovations. This paper aims to study The Element of Surprise as a crucial tactic in Installation Advertising design creativity, it investigates the concept of Installation advertising and highlights its characteristics. It also explores how The Element of Surprise creative formats and tactics are employed in Installation Advertising to achieve the strongest visual impact possible. Then it looks closely through selected international Installation Advertising examples that achieved success through using the element of surprise in creating its advertising message. Finding that the key to a successful Installation advertising is a clever created surprise, Surprise engages the viewers in a way no other media can because the viewer does not expect to experience it. Surprise in Installation advertising has a lasting impact on the minds of viewers. Surprise in Installation advertising can be created via humor, illogicality, or even a shocking visual. Exaggeration, personification, analogy, adaptation, connection are the most used surprise tactics in Installation advertising, intrusion, transformation and illusion are the most often used formats in Installation advertising