At one point Sherlock speaks Mandarin on the phone and asks Watson if she speaks Mandarin. She replies "Not as well as my mother would like." In reality, Lucy Liu grew up speaking Mandarin and holds a degree in Chinese language and culture.
When Joan tells Sherlock about her date's marital answer, he looks up his marital status online at maritalrecords.com. When you look up this site it takes you straight to CBS's website. (Still true in November 2022)
The apartment where the missing executive was found is the same apartment the "Ogre" uses to bring home woman in the show "Gotham".
Two actors from this episode, Craig Bierko and Molly Price, were both featured in separate episodes of the hit HBO series Sex and the City. In this episode of Elementary, they play an executive and his secretary.