Many autistic children have co-occurring behavioural problems influencing core autism symptomology potentially relevant for intervention planning. Parental Expressed Emotion -- reflecting critical, hostile and overprotective comments -- contributes to understanding and predicting behaviour in autistic school-aged children, adolescents and adults and is typically measured using the Five-Minute Speech Sample. However, limitations exist for its use with parents of younger autistic children and so the Autism-Specific Five-Minute Speech Sample was adapted with the goal of better measuring parent Expressed Emotion in the context of childhood autism. The Autism-Specific Five-Minute Speech Sample has not yet been used to explore Expressed Emotion in parents of autistic "preschoolers," nor has the relative predictive utility of the Autism-Specific Five-Minute Speech Sample and Five-Minute Speech Sample been evaluated in the same sample. We compared the two measures from speech samples provided by 51 Australian parents with newly diagnosed autistic preschoolers, including investigating their predictive value for concurrent and subsequent child internalising and externalising behaviour problems. While Autism-Specific Five-Minute Speech Sample Expressed Emotion and Five-Minute Speech Sample Expressed Emotion were associated in this sample, only Autism-Specific Five-Minute Speech Sample codes contributed significant predictive value for concurrent and subsequent child problem behaviour. These preliminary data strengthen the position that the Autism-Specific Five-Minute Speech Sample may better capture Expressed Emotion, than the Five-Minute Speech Sample, among parents of autistic preschool-aged children.