Pictorial health warning labels (HWLs) can communicate the harms of tobacco product use, yet little research exists for cigars. We sought to identify the most effective types of images to pair with newly developed cigar HWLs. In September 2021, we conducted an online survey experiment with US adults who reported using little cigars, cigarillos, or large cigars in the past 30 days (n = 753). After developing nine statements about health effects of cigar use, we randomized participants to view one of three levels of harm visibility paired with each statement, either: (1) an image depicting internal harm not visible outside the body, (2) an image depicting external harm visible outside of the body, or (3) two images depicting both internal and external harm. After viewing each image, participants answered questions on perceived message effectiveness (PME), negative affect, and visual-verbal redundancy (VVR). We used linear mixed models to examine the effect of harm visibility on each outcome, controlling for warning statement. Warnings with both and external harm depictions performed significantly better than the internal harm depictions across all outcomes, including PME (B = 0.21 and B = 0.17), negative affect (B = 0.26 and B = 0.25), and VVR (B = 0.24 and B = 0.17), respectively (all p < .001). Compared to both, the external depiction of harm did not significantly change PME or negative affect but did significantly lower VVR (B = -0.07, p = .01). Future cigar pictorial HWLs may benefit from including images depicting both or external harm depictions. Future research should examine harm visibility's effect for other tobacco pictorial HWLs. The cigar health warning labels (HWLs) proposed by the US Food and Drug Administration are text-only. We conducted an online survey experiment among people who use cigars to examine the effectiveness of warnings with images depicting different levels of harm visibility. We found HWLs with images depicting both an internal and external depiction of cigar harm, or an external depiction of harm alone, performed better overall than images portraying internal depictions of harm. These findings provide important regulatory evidence regarding what type of images may increase warning effectiveness and offer a promising route for future cigar HWL development.