ImportanceEmoji and emoticons are quickly becoming an omnipresent feature of virtual communication. As health care systems increasingly adopt clinical texting applications, it is critical to understand how clinicians use these ideograms with colleagues and how it may affect their interactions.ObjectiveTo evaluate the functions that emoji and emoticons serve in clinical text messages.Design, Setting, and ParticipantsThis qualitative study’s content analysis of clinical text messages from a secure clinical messaging platform was conducted to assess the communicative function of emoji and emoticons. The analysis included messages sent by hospitalists to other health care clinicians. A subset of a random 1% sample of all message threads, which included at least 1 emoji or emoticon, on a clinical texting system used by a large, Midwestern US hospital from July 2020 until March 2021 were analyzed. A total of 80 hospitalists participated in the candidate threads.Main OutcomesWhether and what kind of emoji or emoticon was deployed in each reviewed thread was tabulated by the study team. The communicative function of each emoji and emoticon was assessed according to a prespecified coding scheme.ResultsA total of 80 hospitalists (49 [61%] male; 30 [37%] Asian, 5 [6%] Black or African American, 2 [3%] Hispanic or Latinx, 42 [53%] White; of 41 with age data, 13 [32%] aged 25-34 years, 19 [46%] aged 35-44 years) participated in the 1319 candidate threads. Within the sample of 1319 threads, 7% of threads (155 unique messages) contained at least 1 emoji or emoticon. The majority (94 [61%]) functioned emotively, that is, conveyed the internal state of the sender, and 49 (32%) served to open, maintain, or close communication. No evidence was identified that they caused confusion or were seen as inappropriate.Conclusions and RelevanceThis qualitative study found that when clinicians use emoji and emoticons in secure clinical texting systems, these symbols function primarily to convey new and interactionally salient information. These results suggest that concerns about the professionalism of emoji and emoticon use may be unwarranted.