The 71-year-old was talking to fans at his Arnold Classic Africa sporting event on Saturday when a man drop-kicked him from behind.
The attacker was restrained following the incident in Johannesburg.
However, on Sunday, Schwarzenegger said he would not be taking the case further, adding: "I'm moving on".
The video footage, shared widely on social media, showed Schwarzenegger posing for photos and filming at the event when the man attacks him with a flying kick.
The Terminator star stumbles forward after the kick, while the attacker falls to the ground, where he is immediately restrained by a security guard.
The unnamed man was later handed over to police officers, event officials said.
Schwarzenegger tweeted to his more than four million followers: "I thought I was just jostled by the crowd, which happens a lot. I only realised I was kicked when I saw the video like all of you."
In response to tweets from his fans, he said on Sunday he would not be pressing charges against the attacker.
"We have 90 sports here in South Africa at the @ArnoldSports, and 24,000 athletes of all ages and abilities inspiring all of us to get off the couch. Let's put this spotlight on them," he wrote in a separate message.
The Arnold Classic Africa event takes place every May and features a range of events including bodybuilding and combat sports.
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