Abstract Objective Infantile epileptic spasms syndrome (IESS) is a common and urgent diagnosis with seizure and nonseizure mimics. Evaluation with prolonged video–electroencephalography (EEG) can be time‐consuming and costly. This study investigated the use of EEG review of a single sleep–wake cycle to exclude IESS. Methods We retrospectively reviewed video‐EEG studies to rule out IESS in children between the ages of 2 months and 2 years in the period from January 2019 through June 2020. EEG studies were reviewed from the start of the recording through the first sleep–wake cycle and scored as “normal,” “consistent with IESS,” or “abnormal but not diagnostic of IESS.” Scores were compared to the clinical report created by analysis of the entire video‐EEG. Results Inclusion criteria were met in 238 EEG studies. The mean patient age was 7.6 months. The median duration of the full study was 908 min, compared to 107.5 min for the first sleep–wake cycle only. The median difference in recording time was 801 min, p ‐value < .01. Scored outcomes were similar. Sixty‐eight percent of EEG studies were scored as “normal” on first sleep–wake cycle review as compared to 63% on full study review, 13% scored as “consistent with IESS” compared to 16% and 19% scored as “abnormal but not diagnostic of IESS” compared to 21%. Sensitivity and specificity of the first sleep–wake cycle review for studies “consistent with IESS” was 84% and 100%, respectively. No cases of IESS were scored as normal on first sleep–wake cycle review. Significance A single sleep–wake cycle captured on EEG can triage studies when IESS is suspected. A normal first sleep–wake cycle did not miss cases of IESS and could result in reduced EEG recording time. Because most of these cases presented to an emergency department, a normal first sleep–wake cycle may help providers determine the acuity, or necessity, of further testing.